Simple & Compound Interest

Ladakh Police Constable · Mathematics · 49 practice questions with answers and explanations: 21 Easy, 27 Medium, 1 Hard.

Sample questions

Sample Easy question 1

A sum triples itself in 20 years at simple interest. Find the rate of interest.

  1. 10%
  2. 12%
  3. 9%
  4. 8%
Show answer

Answer: A. SI equals twice the principal over 20 years, so rate = (2 × 100)/20 = 10%.

Sample Easy question 2

Find the simple interest on Rs. 2500 at 4% per annum for 3 years.

  1. 280
  2. 310
  3. 300
  4. 290
Show answer

Answer: C. SI = (2500 × 4 × 3)/100 = 300.

Sample Easy question 3

Find the simple interest on Rs. 2000 at 4% per annum for 3 years.

  1. 230
  2. 240
  3. 250
  4. 220
Show answer

Answer: B. SI = PRT/100 = 2000×4×3/100 = 240.

Sample Medium question 4

A sum becomes Rs. 9680 in 2 years and Rs. 10648 in 3 years at compound interest. Find the rate of interest.

  1. 9%
  2. 10%
  3. 12%
  4. 8%
Show answer

Answer: B. Ratio 10648/9680 = 1.10, so the rate for one year is 10%.

Sample Medium question 5

At what compound interest rate per annum will Rs. 1200 become Rs. 1348.32 in 2 years?

  1. 7%
  2. 6%
  3. 8%
  4. 5%
Show answer

Answer: B. (1348.32/1200) = 1.1236; the square root is 1.06, so the rate is 6% per annum.

Sample Medium question 6

In how many years will Rs. 1000 amount to Rs. 1200 at 5% simple interest per annum?

  1. 3
  2. 6
  3. 4
  4. 5
Show answer

Answer: C. SI = 200; time = 200/(1000 × 0.05) = 4 years.

Sample Hard question 7

Find the compound interest on Rs. 10,000 for 1.5 years at 10% per annum, compounded half-yearly.

  1. 1600
  2. 1576.25
  3. 1500
  4. 1550
Show answer

Answer: B. With 5% per half-year over 3 periods, amount = 10000 × 1.05³ ≈ 11576.25, so CI ≈ 1576.25.

More Mathematics topics for Ladakh Police Constable

Related articles