Ratio and Proportion questions for competitive exams: rules, worked examples and practice

Ratio questions divide an amount into parts in a given ratio or compare two quantities. Convert the ratio to parts, find the value of one part, then multiply.

Published by MockBazaar · Editor: Arun Gupta · Updated 25 October 2026

Key rules and formulas

• If a : b = m : n, then a = total × m ÷ (m + n) and b = total × n ÷ (m + n).
• Multiply or divide every term of a ratio by the same number without changing it.
• Combine a : b and b : c by making the b terms equal.
• In a proportion a : b = c : d, a × d = b × c.

Common traps

• Using the ratio numbers as amounts instead of as parts.
• Reversing the order of the ratio (P : Q vs Q : P).

Where Ratio and Proportion is asked

• IBPS Clerk Prelims (Numerical Ability)
• IBPS PO Prelims (Quantitative Aptitude)
• RRB Group D (Mathematics)
• RRB NTPC CBT 1 (Mathematics)
• SBI Clerk Prelims (Numerical Ability)
• SBI PO Prelims (Quantitative Aptitude)
• SSC CGL Tier 1 (Quantitative Aptitude)
• SSC CGL Tier 2 (Mathematical Abilities)
• SSC CHSL Tier 1 (Quantitative Aptitude)

Worked examples

Related topics

• Partnership
• Boats and Streams
• Compound Interest
• Simple Interest
• Approximation
• Discount and Marked Price
• Profit and Loss
• Averages

Practise Ratio and Proportion in a timed mock