A person saves 10% of his salary every month. If his salary increases by 12% and the expenditure increases by 10%, then what will be the change in his saving per month?
- (a) 20% increase
- (b) 30% increase ✓ UPSC's answer
- (c) 03% decrease
- (d) 02% decrease
Why the answer is (b)
• Take salary 100: saving 10, expenditure 90.
• New salary 112; new expenditure 90 × 1·1 = 99; new saving 112 − 99 = 13.
• Saving rises from 10 to 13, i.e. by 30%: (b).
Why the other options are wrong
- (a) 20% increase
- The increase is 3 on 10, i.e. 30%, not 20%.
- (c) 03% decrease
- Saving increases; it does not decrease.
- (d) 02% decrease
- Saving increases; it does not decrease.
Asked in the CSAT Paper II of the UPSC Civil Services Preliminary Examination 2026, held on 24 May 2026. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.