Pedagogy

CTET Maths MCQ with Answers, Paper 2 (Classes VI-VIII)

234 practice questions on Mathematics, Classes VI-VIII (Paper II) for CTET Paper II (Mathematics and Science), with answers; most also have an explanation or a worked solution. Try each one before you open its answer.

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  1. Q.101

    Solve: (x − 2)/5 + 3 = (x + 4)/3.

    1. A 9.5
    2. B −11.5
    3. C 17.5
    4. D 19
    Show answer

    Correct answer: (A) 9.5

    Multiply both sides by 15: 3(x − 2) + 45 = 5(x + 4), so 3x + 39 = 5x + 20, 2x = 19 and x = 9.5. Check: 7.5/5 + 3 = 4.5 and 13.5/3 = 4.5.

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  2. Q.102

    Two angles are complementary, and one of them is 18° more than the other. What is the larger angle?

    1. A 36°
    2. B 54°
    3. C 81°
    4. D 99°
    Show answer

    Correct answer: (B) 54°

    x + (x + 18°) = 90°, so 2x = 72° and x = 36°. The larger angle is 36° + 18° = 54°; check: 36° + 54° = 90°.

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  3. Q.103

    Which of the following is NOT true for all integers a, b and c? (Assume there is no division by zero.)

    1. A a + (−a) = 0
    2. B a × (b + c) = a × b + a × c
    3. C a ÷ (b ÷ c) = (a ÷ b) ÷ c
    4. D a × (−1) = −a
    Show answer

    Correct answer: (C) a ÷ (b ÷ c) = (a ÷ b) ÷ c

    Division is not associative: (−24) ÷ [(−4) ÷ 2] = (−24) ÷ (−2) = 12, but [(−24) ÷ (−4)] ÷ 2 = 6 ÷ 2 = 3. The other three are the additive inverse, the distributive property and multiplication by −1.

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  4. Q.104

    A polyhedron has 8 faces and 12 vertices. Using Euler's formula, how many edges does it have?

    1. A 6 edges
    2. B 18 edges
    3. C 20 edges
    4. D 22 edges
    Show answer

    Correct answer: (B) 18 edges

    Euler's formula is F + V − E = 2, so 8 + 12 − E = 2 and E = 18. (A hexagonal prism has exactly these numbers.)

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  5. Q.105

    How many bricks, each 25 cm × 12.5 cm × 7.5 cm, are needed to build a wall 10 m long, 30 cm thick and 2.5 m high, if the space taken by mortar is ignored?

    1. A 320
    2. B 3200
    3. C 6400
    4. D 32000
    Show answer

    Correct answer: (B) 3200

    Volume of the wall = 1000 × 30 × 250 = 7500000 cm³ and volume of one brick = 25 × 12.5 × 7.5 = 2343.75 cm³. Number of bricks = 7500000 ÷ 2343.75 = 3200.

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  6. Q.106

    Which of the following sets of four numbers, taken in the given order, is NOT in proportion?

    1. A 4, 6, 10, 15
    2. B 3, 5, 9, 15
    3. C 5, 8, 15, 20
    4. D 2, 7, 6, 21
    Show answer

    Correct answer: (C) 5, 8, 15, 20

    Four numbers are in proportion when the product of the extremes equals the product of the means. For 5, 8, 15, 20: 5 × 20 = 100 but 8 × 15 = 120. The others pass (4 × 15 = 6 × 10, 3 × 15 = 5 × 9, 2 × 21 = 7 × 6).

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  7. Q.107

    8 tailors stitch 120 shirts in a day. Working at the same rate, how many shirts will 14 tailors stitch in a day?

    1. A 68.6
    2. B 126
    3. C 210
    4. D 1680
    Show answer

    Correct answer: (C) 210

    One tailor stitches 120 ÷ 8 = 15 shirts a day, so 14 tailors stitch 14 × 15 = 210 shirts (direct proportion).

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  8. Q.108

    A shopkeeper buys a fan for ₹1,250 and sells it for ₹1,425. What is his profit per cent?

    1. A 12.3%
    2. B 14%
    3. C 17.5%
    4. D 114%
    Show answer

    Correct answer: (B) 14%

    Profit = 1425 − 1250 = ₹175. Profit % = (175 ÷ 1250) × 100 = 14%, calculated on the cost price.

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  9. Q.109

    How many diagonals does a polygon with 7 sides (a heptagon) have?

    1. A 4 diagonals
    2. B 14 diagonals
    3. C 21 diagonals
    4. D 28 diagonals
    Show answer

    Correct answer: (B) 14 diagonals

    From each vertex, diagonals go to 7 − 3 = 4 other vertices (not to itself or its two neighbours). 7 × 4 = 28 counts each diagonal twice, so there are 28 ÷ 2 = 14 diagonals.

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  10. Q.110

    Consider the statements: 1. If a number is divisible by 3, it is divisible by 9. 2. If a number exactly divides each of two numbers, it exactly divides their difference. 3. If a number is divisible by both 3 and 5, it is divisible by 15. Which of these are true?

    1. A Only 1 and 2
    2. B Only 2 and 3
    3. C Only 3
    4. D 1, 2 and 3
    Show answer

    Correct answer: (B) Only 2 and 3

    Statement 1 is false: 12 is divisible by 3 but not by 9. Statement 2 is a property of divisibility, and statement 3 is true because 3 and 5 are co-prime, so their product 15 divides the number.

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  11. Q.111

    The angles of a triangle are in the ratio 2 : 3 : 4. The triangle is:

    1. A Acute-angled and scalene
    2. B Right-angled and scalene
    3. C Obtuse-angled and scalene
    4. D Acute-angled and isosceles
    Show answer

    Correct answer: (A) Acute-angled and scalene

    2x + 3x + 4x = 180°, so x = 20° and the angles are 40°, 60° and 80°. All are less than 90° and all are different, so the triangle is acute-angled and scalene.

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  12. Q.112

    Consider the following statements. 1. An equilateral triangle has rotational symmetry of order 6. 2. A circle has infinitely many lines of symmetry. Which of the statements is/are correct?

    1. A Only 1
    2. B Only 2
    3. C Both 1 and 2
    4. D Neither 1 nor 2
    Show answer

    Correct answer: (B) Only 2

    An equilateral triangle looks the same after turns of 120°, 240° and 360°, so its order is 3, not 6; statement 1 is false. Every line through the centre of a circle is a line of symmetry, so statement 2 is true.

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  13. Q.113

    Which of the following numbers can NOT be a perfect square?

    1. A 4,48,900
    2. B 1,05,625
    3. C 64,000
    4. D 7,29,316
    Show answer

    Correct answer: (C) 64,000

    A perfect square always ends in an even number of zeros, and 64,000 ends in three zeros, so it is not a square. The others are squares: 325² = 1,05,625, 670² = 4,48,900 and 854² = 7,29,316.

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  14. Q.114

    How many factors does 144 have?

    1. A 12
    2. B 14
    3. C 16
    4. D 15
    Show answer

    Correct answer: (D) 15

    The factors of 144 are 1, 2, 3, 4, 6, 8, 9, 12, 16, 18, 24, 36, 48, 72 and 144, that is 15. The count is odd because 144 = 12 × 12 is a perfect square and 12 is counted only once.

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  15. Q.115

    1729, the Hardy-Ramanujan number, is the smallest number that can be written as the sum of two cubes in two different ways. Which are the two ways?

    1. A 1³ + 12³ and 9³ + 10³
    2. B 2³ + 12³ and 9³ + 10³
    3. C 1³ + 12³ and 8³ + 11³
    4. D 6³ + 11³ and 9³ + 10³
    Show answer

    Correct answer: (A) 1³ + 12³ and 9³ + 10³

    1 + 1,728 = 1,729 and 729 + 1,000 = 1,729. The other pairs fail: 2³ + 12³ = 1,736, 8³ + 11³ = 1,843 and 6³ + 11³ = 1,547.

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  16. Q.116

    The HCF of two numbers is 16 and their LCM is 480. If one of the numbers is 96, what is the other number?

    1. A 160
    2. B 80
    3. C 120
    4. D 30
    Show answer

    Correct answer: (B) 80

    For two numbers, HCF × LCM = product of the numbers, so the other number = (16 × 480) ÷ 96 = 80. Check: the HCF of 96 and 80 is 16 and their LCM is 480.

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  17. Q.117

    Which of the following figures has rotational symmetry of order 2 but no line of symmetry?

    1. A A parallelogram that is neither a rectangle nor a rhombus
    2. B An isosceles trapezium
    3. C A kite that is not a rhombus
    4. D A scalene triangle
    Show answer

    Correct answer: (A) A parallelogram that is neither a rectangle nor a rhombus

    Such a parallelogram looks the same after a half turn about the point where its diagonals meet, but no fold makes its two halves match. An isosceles trapezium and a kite have one line of symmetry and no rotational symmetry of order more than 1; a scalene triangle has neither.

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  18. Q.118

    Consider the following statements:

    1. 0.5% of a quantity is the same as half of that quantity.

    2. If A's salary is 25% more than B's, then B's salary is 20% less than A's.

    Which of these is/are correct?

    1. A Only 1
    2. B Only 2
    3. C Both 1 and 2
    4. D Neither 1 nor 2
    Show answer

    Correct answer: (B) Only 2

    Statement 1 is wrong: 0.5% means 0.5/100 = 1/200 of the quantity, while half of it is 50%. Statement 2 is correct: if B = 100, then A = 125, and 25 is 20% of 125.

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  19. Q.119

    In a village of 1,260 voters, 3/7 voted for candidate A and 2/5 of the remaining voters voted for candidate B. How many voters voted for neither A nor B?

    1. A 720
    2. B 288
    3. C 216
    4. D 432
    Show answer

    Correct answer: (D) 432

    A got 3/7 × 1,260 = 540 votes, leaving 720 voters. B got 2/5 × 720 = 288, so 720 − 288 = 432 voted for neither. Taking 2/5 of all 1,260 instead of the remaining voters gives 216.

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  20. Q.120

    A cuboidal water tank is 2.5 m long, 1.6 m wide and 1.2 m deep. How many litres of water can it hold when full?

    1. A 48 litres
    2. B 480 litres
    3. C 4,800 litres
    4. D 48,000 litres
    Show answer

    Correct answer: (C) 4,800 litres

    Volume = 2.5 × 1.6 × 1.2 = 4.8 m³. Since 1 m³ = 1000 litres, the tank holds 4.8 × 1000 = 4,800 litres.

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  21. Q.121

    A cement company makes a profit of ₹9 on each bag of white cement and a loss of ₹6 on each bag of grey cement. In a month it sells 2,400 bags of white cement and 4,000 bags of grey cement. What is its result for the month?

    1. A Profit of ₹2,400
    2. B Loss of ₹2,400
    3. C Profit of ₹45,600
    4. D Profit of ₹21,600
    Show answer

    Correct answer: (B) Loss of ₹2,400

    Taking profit as positive and loss as negative: 2,400 × 9 + 4,000 × (−6) = 21,600 − 24,000 = −2,400, a loss of ₹2,400. Adding the two amounts (₹45,600) ignores the signs, and ₹21,600 is only the profit on white cement.

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  22. Q.122

    Each of the two equal sides of an isosceles triangle is 5 cm longer than its base. If the perimeter of the triangle is 61 cm, what is the length of the base?

    1. A 17 cm
    2. B 20.3 cm
    3. C 22 cm
    4. D 28 cm
    Show answer

    Correct answer: (A) 17 cm

    Let the base be b cm; each equal side is b + 5. Then b + 2(b + 5) = 61, so 3b + 10 = 61 and b = 17. Check: 17 + 22 + 22 = 61.

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  23. Q.123

    Which of the following is NOT a correct way of writing 36 as the sum of two prime numbers?

    1. A 11 + 25
    2. B 5 + 31
    3. C 7 + 29
    4. D 17 + 19
    Show answer

    Correct answer: (A) 11 + 25

    5, 31, 7, 29, 17 and 19 are all prime, but 25 = 5 × 5 is composite, so 11 + 25 is not a sum of two primes.

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  24. Q.124

    In right triangles PQR and XYZ, angle Q = angle Y = 90°, PR = XZ = 13 cm and PQ = XY = 5 cm. Which of the following is correct?

    1. A They are congruent by RHS, and QR = YZ = 12 cm
    2. B They are congruent by SAS, and QR = YZ = 8 cm
    3. C They need not be congruent, since only two sides are known
    4. D They are congruent by RHS, and QR = YZ = 18 cm
    Show answer

    Correct answer: (A) They are congruent by RHS, and QR = YZ = 12 cm

    The hypotenuses and one pair of sides are equal, so ΔPQR ≅ ΔXYZ by RHS. By Pythagoras, QR = √(13² − 5²) = √144 = 12 cm, and YZ is the same.

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  25. Q.125

    A bag contains 3.75 kg of rice, 1.6 kg of dal and 850 g of sugar. What is the total weight of the bag's contents?

    1. A 13.85 kg
    2. B 6.2 kg
    3. C 5.435 kg
    4. D 4.76 kg
    Show answer

    Correct answer: (B) 6.2 kg

    850 g = 0.85 kg. Lining up the decimal points: 3.75 + 1.60 + 0.85 = 6.20 kg. Writing 850 g as 8.5 kg or 0.085 kg is a conversion error, and 4.76 kg comes from adding 1.6 as if it were 0.16.

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  26. Q.126

    The length of a rectangle is 7 cm more than its breadth, and its perimeter is 90 cm. What is its length?

    1. A 26 cm
    2. B 19 cm
    3. C 45 cm
    4. D 48.5 cm
    Show answer

    Correct answer: (A) 26 cm

    Let the breadth be b. Then 2(b + 7 + b) = 90, so 2b + 7 = 45 and b = 19; the length is 26 cm. Check: 2 × (26 + 19) = 90.

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  27. Q.127

    Consider the following statements:

    1. If x and y are in direct proportion, then x + y has the same value for every pair of values.

    2. If x and y are in inverse proportion and x is doubled, then y is also doubled.

    Which of these is/are correct?

    1. A Only 1
    2. B Only 2
    3. C Both 1 and 2
    4. D Neither 1 nor 2
    Show answer

    Correct answer: (D) Neither 1 nor 2

    Both are wrong. In direct proportion it is x/y, not x + y, that stays constant (for y = 3x, the pairs 1, 3 and 2, 6 have sums 4 and 8). In inverse proportion xy is constant, so when x is doubled, y is halved.

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  28. Q.128

    Which decimal is equal to 7/16?

    1. A 0.4375
    2. B 0.716
    3. C 0.4357
    4. D 0.375
    Show answer

    Correct answer: (A) 0.4375

    7/16 = (7 × 625)/(16 × 625) = 4,375/10,000 = 0.4375; dividing 7 by 16 gives the same result. 0.375 is 3/8.

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  29. Q.129

    When written as capital block letters, which of the following has rotational symmetry of order 2 but no line of symmetry?

    1. A Z
    2. B E
    3. C V
    4. D A
    Show answer

    Correct answer: (A) Z

    Z looks the same after a half turn (180°) but has no line of symmetry. E has a horizontal line of symmetry, V and A have a vertical one, and none of these three looks the same after a half turn.

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  30. Q.130

    Which expression stands for 'one-third of the sum of y and 8'?

    1. A y/3 + 8
    2. B (y + 8)/3
    3. C 3(y + 8)
    4. D 3y + 8
    Show answer

    Correct answer: (B) (y + 8)/3

    First form the sum y + 8, then take one-third of the whole sum: (y + 8)/3. The expression y/3 + 8 takes one-third of y only.

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  31. Q.131

    In a table, x takes the values 4, 6 and 10, and the corresponding values of y are 30, 20 and 12. Which statement is correct?

    1. A x and y are in direct proportion
    2. B x and y are in inverse proportion, with xy = 120
    3. C x and y are in inverse proportion, with xy = 60
    4. D x and y are in neither direct nor inverse proportion
    Show answer

    Correct answer: (B) x and y are in inverse proportion, with xy = 120

    4 × 30 = 6 × 20 = 10 × 12 = 120, so the product xy is constant and x and y are in inverse proportion. The ratio x/y is not constant (4/30 is not equal to 6/20), so they are not in direct proportion.

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  32. Q.132

    A rectangular park is 63 m long and 16 m wide. Asha walks from one corner to the opposite corner along the diagonal instead of along two sides. How many metres does she save?

    1. A 14 m
    2. B 16 m
    3. C 65 m
    4. D 79 m
    Show answer

    Correct answer: (A) 14 m

    Diagonal = √(63² + 16²) = √(3969 + 256) = √4225 = 65 m. Along two sides she would walk 63 + 16 = 79 m, so she saves 79 − 65 = 14 m.

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  33. Q.133

    If 49x² + kx + 16 is a perfect square and k is positive, the value of k is:

    1. A 11
    2. B 28
    3. C 56
    4. D 112
    Show answer

    Correct answer: (C) 56

    49x² = (7x)² and 16 = 4², so the expression is (7x + 4)² = 49x² + 2 × 7x × 4 + 16 = 49x² + 56x + 16; hence k = 56.

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  34. Q.134

    How is the number 30,507,040 (written with international commas) read in the international system?

    1. A Three hundred five million seven thousand forty
    2. B Three million fifty thousand seven hundred forty
    3. C Thirty million fifty-seven thousand forty
    4. D Thirty million five hundred seven thousand forty
    Show answer

    Correct answer: (D) Thirty million five hundred seven thousand forty

    The international periods are millions, thousands and ones: 30 | 507 | 040, so the number is thirty million five hundred seven thousand forty. In the Indian system the same number is 3,05,07,040, three crore five lakh seven thousand forty.

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  35. Q.135

    How many natural numbers lie between 37² and 38², not counting 37² and 38² themselves?

    1. A 37
    2. B 75
    3. C 73
    4. D 74
    Show answer

    Correct answer: (D) 74

    Between n² and (n + 1)² there are 2n natural numbers, none of which is a perfect square. For n = 37 this is 2 × 37 = 74; check: 1,444 − 1,369 − 1 = 74.

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  36. Q.136

    Subtract 4x² − 3x + 2 from 7x² + x − 5.

    1. A 3x² + 4x − 7
    2. B 3x² − 2x − 3
    3. C 11x² − 2x − 3
    4. D 3x² + 4x − 3
    Show answer

    Correct answer: (A) 3x² + 4x − 7

    (7x² + x − 5) − (4x² − 3x + 2) = 7x² + x − 5 − 4x² + 3x − 2 = 3x² + 4x − 7. Every sign of the expression being subtracted must change.

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  37. Q.137

    A kite is a quadrilateral with two pairs of equal adjacent sides. Which of the following is NOT necessarily true for a kite?

    1. A Its diagonals are perpendicular to each other
    2. B One of its diagonals bisects the other
    3. C It has at least one line of symmetry
    4. D Its opposite sides are equal
    Show answer

    Correct answer: (D) Its opposite sides are equal

    In a kite, the diagonal joining the two vertices where equal sides meet is a line of symmetry; it is perpendicular to the other diagonal and bisects it. The equal sides are adjacent, not opposite, so opposite sides need not be equal.

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  38. Q.138

    Two tankers hold 850 litres and 680 litres of kerosene. What is the greatest capacity of a container that can measure the kerosene of each tanker an exact number of times?

    1. A 85 litres
    2. B 170 litres
    3. C 340 litres
    4. D 3,400 litres
    Show answer

    Correct answer: (B) 170 litres

    The capacity must be a common factor of 850 and 680, and the greatest such factor is the HCF. 850 = 2 × 5² × 17 and 680 = 2³ × 5 × 17, so HCF = 2 × 5 × 17 = 170 litres (3,400 is the LCM).

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  39. Q.139

    If a : b = 2 : 3 and b : c = 4 : 5, then a : b : c is:

    1. A 2 : 3 : 5
    2. B 6 : 12 : 15
    3. C 8 : 12 : 15
    4. D 2 : 12 : 5
    Show answer

    Correct answer: (C) 8 : 12 : 15

    Make the b terms equal: a : b = 8 : 12 (multiplying by 4) and b : c = 12 : 15 (multiplying by 3). So a : b : c = 8 : 12 : 15.

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  40. Q.140

    Ramesh spends 2/5 of his monthly salary on rent and 1/3 of the remaining amount on food. He saves the rest, which is ₹13,200. What is his monthly salary?

    1. A ₹33,000
    2. B ₹49,500
    3. C ₹22,000
    4. D ₹19,800
    Show answer

    Correct answer: (A) ₹33,000

    After rent 3/5 of the salary is left, and food takes 1/3 of that, i.e. 1/5 of the salary. Savings = 3/5 − 1/5 = 2/5 of the salary = ₹13,200, so the salary is 13,200 × 5/2 = ₹33,000. Taking food as 1/3 of the whole salary wrongly gives ₹49,500.

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  41. Q.141

    By selling a chair for ₹1,316, a carpenter suffers a loss of 6%. What was the cost price of the chair?

    1. A ₹1,237
    2. B ₹1,395
    3. C ₹1,400
    4. D ₹1,450
    Show answer

    Correct answer: (C) ₹1,400

    Selling price = 94% of cost price, so CP = 1316 × 100 ÷ 94 = ₹1,400. Check: 6% of 1400 is 84, and 1400 − 84 = 1316.

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  42. Q.142

    Without adding term by term, find 1 + 3 + 5 + ... + 29, the sum of the consecutive odd numbers from 1 to 29.

    1. A 435
    2. B 196
    3. C 256
    4. D 225
    Show answer

    Correct answer: (D) 225

    The sum of the first n odd numbers is n². From 1 to 29 there are (29 + 1) ÷ 2 = 15 odd numbers, so the sum is 15² = 225. (435 is the sum of all the numbers from 1 to 29.)

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  43. Q.143

    ₹8,000 is invested for 1 year at 10% per annum, compounded half-yearly. What is the amount at the end of the year?

    1. A ₹8,400
    2. B ₹8,800
    3. C ₹8,820
    4. D ₹9,680
    Show answer

    Correct answer: (C) ₹8,820

    Compounding half-yearly means a rate of 5% for each of the 2 half-years: 8000 × 1.05 × 1.05 = ₹8,820.

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  44. Q.144

    Find the value of 2a² − 3ab + b when a = −2 and b = 3.

    1. A −7
    2. B 13
    3. C 37
    4. D 29
    Show answer

    Correct answer: (D) 29

    2a² = 2 × 4 = 8, −3ab = −3 × (−2) × 3 = 18 and b = 3, so the value is 8 + 18 + 3 = 29.

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  45. Q.145

    Solve: 3(2y − 5) − 4(y − 6) = 30.

    1. A 5.5
    2. B 10.5
    3. C 19.5
    4. D 34.5
    Show answer

    Correct answer: (B) 10.5

    Open the brackets: 6y − 15 − 4y + 24 = 30, so 2y + 9 = 30 and y = 10.5. Note that −4 × (−6) = +24.

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  46. Q.146

    A milk vendor supplies 32 litres of milk in the morning and 68 litres in the evening. If milk costs ₹45 per litre, how much money does he receive in a day?

    1. A ₹4,500
    2. B ₹3,092
    3. C ₹1,508
    4. D ₹5,400
    Show answer

    Correct answer: (A) ₹4,500

    Money = 32 × 45 + 68 × 45 = (32 + 68) × 45 = 100 × 45 = ₹4,500, using the distributive property. ₹3,092 comes from wrongly working out 32 + 68 × 45 without brackets.

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  47. Q.147

    ₹5,200 is divided among three friends in the ratio 1/2 : 1/3 : 1/4. What is the largest share?

    1. A ₹1,200
    2. B ₹1,600
    3. C ₹2,400
    4. D ₹2,600
    Show answer

    Correct answer: (C) ₹2,400

    Multiply each fraction by 12 (the LCM of 2, 3 and 4): 1/2 : 1/3 : 1/4 = 6 : 4 : 3. One part = 5200 ÷ 13 = ₹400, so the largest share is 6 × 400 = ₹2,400.

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  48. Q.148

    The number of bacteria in a culture doubles every 20 minutes. If there are 500 bacteria at the start, how many will there be after 3 hours?

    1. A 5,12,000
    2. B 1,28,000
    3. C 2,56,000
    4. D 9,000
    Show answer

    Correct answer: (C) 2,56,000

    3 hours = 180 minutes = 9 doubling periods, so the number becomes 500 × 2⁹ = 500 × 512 = 2,56,000. Counting 8 or 10 doublings gives 1,28,000 or 5,12,000, and 500 × 18 = 9,000 confuses 2⁹ with 2 × 9.

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  49. Q.149

    If 9 : x = 15 : 35, what is the value of x?

    1. A 15
    2. B 21
    3. C 29
    4. D 41
    Show answer

    Correct answer: (B) 21

    In a proportion the product of the extremes equals the product of the means: 15x = 9 × 35 = 315, so x = 21. Check: 9 : 21 = 3 : 7 = 15 : 35.

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  50. Q.150

    The angles of a triangle are (x + 10)°, (2x − 20)° and (3x − 50)°. What is the largest angle of the triangle?

    1. A 40°
    2. B 50°
    3. C 60°
    4. D 70°
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    Correct answer: (D) 70°

    (x + 10) + (2x − 20) + (3x − 50) = 180 gives 6x − 60 = 180, so x = 40. The angles are 50°, 60° and 70°, and the largest is 70°.

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