CBSE Class 8 Mathematics Ratio and Proportion MCQs Set 45

Download CBSE MCQs for Class 8 Mathematics: Ratio and Proportion

Review structured MCQ sets for Class 8 Mathematics Ratio and Proportion. Built according to official CBSE guidelines, these downloadable questions support daily revision and core concept reinforcement.

Chapter-wise Objective Questions: Ratio and Proportion

Access the complete set of multiple-choice questions for Ratio and Proportion below. This focused format allows students to isolate specific topics for thorough review and uninterrupted practice alongside official CBSE textbooks.

Multiple Choice Questions

Question 1: Find the compound ratio of 1 : 2, 3 : 5 and 5 : 9.
(a) 1 : 3
(b) 3 : 10
(c) 1 : 6
(d) 2 : 9
Show Answer & Explanation

Answer: (c) 1 : 6

Explanation:
1. Multiply the antecedents and the consequents: (1 × 3 × 5) : (2 × 5 × 9) = 15 : 90.
2. 15 : 90 = 1 : 6.

Teacher's Note:
1. Compound ratio = product of antecedents : product of consequents.
2. Reduce the final ratio to lowest terms.

Question 2: Find the compound ratio of 5 : 7, 15 : 14 and 98 : 75.
(a) 7 : 5
(b) 1 : 2
(c) 2 : 1
(d) 1 : 1
Show Answer & Explanation

Answer: (d) 1 : 1

Explanation:
1. (5 × 15 × 98) : (7 × 14 × 75) = 7350 : 7350.
2. So the ratio is 1 : 1.

Teacher's Note:
1. Cancel common factors before multiplying.
2. 98 = 7 × 14 and 75 = 5 × 15, which cancels everything.

Question 3: Find the subduplicate ratio of 16 : 25.
(a) 256 : 625
(b) 4 : 25
(c) 4 : 5
(d) 8 : 5
Show Answer & Explanation

Answer: (c) 4 : 5

Explanation:
1. The subduplicate ratio of a : b is √a : √b.
2. √16 : √25 = 4 : 5.

Teacher's Note:
1. Subduplicate means square roots of both terms.
2. Duplicate ratio would be the squares.

Question 4: Find the subtriplicate ratio of 343 : 729.
(a) 7 : 9
(b) 49 : 81
(c) 343 : 9
(d) 7 : 27
Show Answer & Explanation

Answer: (a) 7 : 9

Explanation:
1. Subtriplicate ratio of a : b is ∛a : ∛b.
2. ∛343 : ∛729 = 7 : 9.

Teacher's Note:
1. Subtriplicate means cube roots of both terms.
2. 7³ = 343 and 9³ = 729.

Question 5: Find the duplicate ratio of 14 : 17 and the triplicate ratio of 3 : 5.
(a) 196 : 289 and 9 : 25
(b) 196 : 289 and 27 : 125
(c) 28 : 34 and 9 : 15
(d) 14 : 17 and 27 : 125
Show Answer & Explanation

Answer: (b) 196 : 289 and 27 : 125

Explanation:
1. Duplicate ratio = squares: 14² : 17² = 196 : 289.
2. Triplicate ratio = cubes: 3³ : 5³ = 27 : 125.

Teacher's Note:
1. Duplicate = squares, triplicate = cubes.
2. Do not confuse with doubling the terms.

Question 6: Find the mean proportional between 0.5 and 1922.
(a) 31
(b) 30
(c) 32
(d) 961
Show Answer & Explanation

Answer: (a) 31

Explanation:
1. Mean proportional = √(0.5 × 1922) = √961.
2. √961 = 31.

Teacher's Note:
1. Mean proportional of a and b is √(ab).
2. 31² = 961.

Question 7: If 30 men do a piece of work in 27 days, in what time can 18 men do another piece of work three times as great?
(a) 81 days
(b) 135 days
(c) 90 days
(d) 45 days
Show Answer & Explanation

Answer: (b) 135 days

Explanation:
1. Work done by 30 men in 27 days = 810 man-days for one unit.
2. Three times the work needs 2430 man-days.
3. Days = 2430 / 18 = 135.

Teacher's Note:
1. Work is proportional to men × days.
2. More work and fewer men both increase the time.

Question 8: Divide Rs. 324.36 into three parts in the proportion 5 : 6 : 7.
(a) Rs. 92.10, Rs. 106.12, Rs. 126.14
(b) Rs. 90, Rs. 120, Rs. 108
(c) Rs. 80, Rs. 121, Rs. 109
(d) Rs. 90.10, Rs. 108.12, Rs. 126.14
Show Answer & Explanation

Answer: (d) Rs. 90.10, Rs. 108.12, Rs. 126.14

Explanation:
1. Sum of ratio terms = 18, so one part = 324.36 / 18 = Rs. 18.02.
2. Shares: 5 × 18.02 = 90.10, 6 × 18.02 = 108.12, 7 × 18.02 = 126.14.

Teacher's Note:
1. Find the value of one ratio part first.
2. The three shares must add up to Rs. 324.36.

Question 9: Divide Rs. 625 among A, B and C such that A gets 2/9 of B's share and C gets 3/4 of A's share. The shares of A, B and C respectively are
(a) Rs. 100, Rs. 450, Rs. 75
(b) Rs. 90, Rs. 300, Rs. 60
(c) Rs. 100, Rs. 400, Rs. 70
(d) Rs. 450, Rs. 100, Rs. 75
Show Answer & Explanation

Answer: (a) Rs. 100, Rs. 450, Rs. 75

Explanation:
1. Let B's share = 9k. Then A = 2k and C = (3/4) × 2k = 1.5k.
2. Total = 9k + 2k + 1.5k = 12.5k = 625, so k = 50.
3. A = 100, B = 450, C = 75.

Teacher's Note:
1. Express every share in terms of one variable.
2. Check: 100 + 450 + 75 = 625.

Question 10: Two sums of money are proportional to 8 : 9. If the first is Rs. 20, what is the other?
(a) Rs. 225
(b) Rs. 22.5
(c) Rs. 2250
(d) Rs. 2.25
Show Answer & Explanation

Answer: (b) Rs. 22.5

Explanation:
1. 8 : 9 = 20 : x, so x = 20 × 9 / 8 = 22.5.

Teacher's Note:
1. Scale both terms by the same factor.
2. 20 / 8 = 2.5 and 2.5 × 9 = 22.5.

Question 11: Find the number which, when added to each term of the ratio 11 : 23, makes it equal to the ratio 4 : 7.
(a) 5
(b) 10
(c) 20
(d) 15
Show Answer & Explanation

Answer: (a) 5

Explanation:
1. (11 + x) / (23 + x) = 4 / 7.
2. 77 + 7x = 92 + 4x, so 3x = 15 and x = 5.
3. Check: 16 : 28 = 4 : 7.

Teacher's Note:
1. Cross-multiply to form a linear equation.
2. Always verify by substituting back.

Question 12: The sum of two numbers is 40 and their difference is 4. The ratio of the numbers is
(a) 11 : 10
(b) 9 : 11
(c) 10 : 11
(d) 11 : 9
Show Answer & Explanation

Answer: (d) 11 : 9

Explanation:
1. Larger = (40 + 4) / 2 = 22 and smaller = (40 − 4) / 2 = 18.
2. Ratio = 22 : 18 = 11 : 9.

Teacher's Note:
1. Sum and difference give the two numbers directly.
2. The ratio of larger to smaller is asked.

Question 13: If 5 men or 7 women can earn Rs. 875 per day, how much would 10 men and 5 women earn per day?
(a) Rs. 2375
(b) Rs. 2300
(c) Rs. 2400
(d) Rs. 2735
Show Answer & Explanation

Answer: (a) Rs. 2375

Explanation:
1. 1 man earns 875 / 5 = Rs. 175 and 1 woman earns 875 / 7 = Rs. 125.
2. 10 men + 5 women earn 1750 + 625 = Rs. 2375.

Teacher's Note:
1. Find the earnings of one person of each kind.
2. Add the two totals.

Question 14: If the wages of 12 workers for 5 days are Rs. 7500, find the wages of 17 workers for 6 days.
(a) Rs. 12800
(b) Rs. 13005
(c) Rs. 13000
(d) Rs. 12750
Show Answer & Explanation

Answer: (d) Rs. 12750

Explanation:
1. Wage of 1 worker for 1 day = 7500 / 60 = Rs. 125.
2. 17 × 6 × 125 = Rs. 12750.

Teacher's Note:
1. Wages are proportional to workers × days.
2. Reduce to one worker for one day first.

Question 15: Find the fourth proportional to 6, 8 and 15.
(a) 20
(b) 15
(c) 25
(d) 10
Show Answer & Explanation

Answer: (a) 20

Explanation:
1. d = (8 × 15) / 6 = 20.

Teacher's Note:
1. Fourth proportional d: a : b = c : d.
2. 6 : 8 = 15 : 20 = 3 : 4.

Question 16: The third proportional to 5 and 10 is
(a) 15
(b) 20
(c) 2.5
(d) 25
Show Answer & Explanation

Answer: (b) 20

Explanation:
1. a : b = b : c, so c = b² / a = 100 / 5 = 20.

Teacher's Note:
1. Third proportional c satisfies b² = ac.
2. 5 : 10 = 10 : 20.

Question 17: The ratio of the number of boys to girls in a school is 2 : 5. If there are 350 students in total, the number of girls is
(a) 250
(b) 150
(c) 100
(d) 200
Show Answer & Explanation

Answer: (a) 250

Explanation:
1. Girls = 350 × 5 / 7 = 250.

Teacher's Note:
1. Divide the total in the ratio 2 : 5.
2. Boys = 100 and girls = 250.

Free study material for Mathematics

Multiple Choice Questions (MCQs) for Class 8 Mathematics Ratio and Proportion

About Ratio and Proportion MCQs for Class 8 Mathematics

Explore reliable practice questions for Ratio and Proportion tailored for Class 8 Mathematics learners. Use these multiple-choice formats to evaluate preparedness and strengthen problem-solving skills.

How to Verify Your MCQ Answers

Cross-reference your completed choices with comprehensive NCERT solutions for Class 8 Mathematics to ensure absolute clarity across all sub-topics in this chapter.

Enhance Speed with Online MCQ Tests

Explore our broader library of printable assignments, chapter notes, and mock tests designed to support continuous revision and secure higher marks in CBSE assessments.

FAQs

Where can I access latest CBSE Class 8 Mathematics Ratio and Proportion MCQs Set 45?

You can get most exhaustive CBSE Class 8 Mathematics Ratio and Proportion MCQs Set 45 for free on StudiesToday.com. These MCQs for Class 8 Mathematics are updated for the 2026-27 academic session as per CBSE examination standards.

Are Assertion-Reasoning and Case-Study MCQs included in the Mathematics Class 8 material?

Yes, our CBSE Class 8 Mathematics Ratio and Proportion MCQs Set 45 include the latest type of questions, such as Assertion-Reasoning and Case-based MCQs. 50% of the CBSE paper is now competency-based.

How do practicing Mathematics MCQs help in scoring full marks in Class 8 exams?

By solving our CBSE Class 8 Mathematics Ratio and Proportion MCQs Set 45, Class 8 students can improve their accuracy and speed which is important as objective questions provide a chance to secure 100% marks in the Mathematics.

Do you provide answers and explanations for CBSE Class 8 Mathematics Ratio and Proportion MCQs Set 45?

Yes, Mathematics MCQs for Class 8 have answer key and brief explanations to help students understand logic behind the correct option as its important for 2026 competency-focused CBSE exams.

Can I practice these Mathematics Class 8 MCQs online?

Yes, you can also access online interactive tests for CBSE Class 8 Mathematics Ratio and Proportion MCQs Set 45 on StudiesToday.com as they provide instant answers and score to help you track your progress in Mathematics.