Level 4 pre-test mathematics: percentages, ratios and interest with worked examples

By Loksewa Hack · Updated November 1, 2026 · 2 min read

Applied mathematics becomes easier when you turn a word problem into a clear calculation. This guide covers three skills named in section 8.1 of the Sangathit Sanstha Level 4 pre-qualification syllabus: percentages, ratios and interest. These are original learning examples, not reproduced exam questions.

1. Percentages: identify the starting amount

A service originally costs NPR 800 and receives a 10% discount. The discount is 800 × 10/100 = NPR 80, so the amount payable is NPR 720. A common mistake is subtracting 10 rupees instead of 10 percent.

If a price rises from NPR 500 to NPR 575, the increase is NPR 75. Divide by the original price: 75/500 × 100 = 15%. Using the new price as the denominator answers a different question.

2. Ratios: calculate the value of one part

Divide NPR 75,000 between two offices in the ratio 2:3. There are five parts. One part is 75,000/5 = 15,000. The first office receives NPR 30,000 and the second NPR 45,000. Check that the two amounts add to the original total.

3. Simple interest: keep time in the right unit

For NPR 20,000 at 8% per year for nine months, convert time to 9/12 of a year. Interest = 20,000 × 8/100 × 9/12 = NPR 1,200. The final amount is NPR 21,200, assuming no fees or tax.

For annual compound interest on NPR 20,000 at 10% for two years, the amount is 20,000 × 1.10 × 1.10 = NPR 24,200. Interest is NPR 4,200. Simple interest for the same principal, rate and time is NPR 4,000. The difference arises because the second year earns interest on the first year’s interest.

A practical checking routine

1. Write the given amount, rate and time.
2. Convert months into years when the rate is annual.
3. Decide whether the question asks for interest or the final amount.
4. Estimate the likely answer before calculating.
5. Check the units and the original total.

The official pre-test document specifies that calculators are not allowed. Practise manageable fractions and percentage conversions by hand. Our short learning sessions use their own scoring and are not full official mocks.

Practise bilingual mathematics questions and record whether each error came from reading, choosing the method or arithmetic.

Official Level 4 pre-test syllabus, section 8.1. Source checked 1 November 2026; verify amendments for your recruitment cycle.