Selected MCQ

Current Question
A sum of money doubles itself in 5 years at simple interest. What is the rate of interest?
  • A. 10%
  • B. 20%
  • C. 25%
  • D. 40%
Correct Answer: B
Explanation:
Doubling ⇒ SI = principal → rate = 100/5 = 20%.
Related Question 1
A sum of money doubles in 5 years at simple interest. In how many years will it become four times ____.
  • A. 10 years
  • B. 12 years
  • C. 15 years
  • D. 20 years
Correct Answer: C
Explanation:
Doubling means 100% interest in 5 years → quadruple = 300% → 15 years.
Related Question 2
There is a 60% increase in a sum in 6 years at simple interest. What will be the compound interest on Rs. 12000 for 3 years at the same rate?
  • A. Rs. 2160
  • B. Rs. 3120
  • C. Rs. 3972
  • D. Rs. 6240
Correct Answer: C
Explanation:
Rate = 10%, CI = 12000[(1.1)³ − 1] = 3972.
Related Question 3
The simple interest on Rs. 12000 for 5 years is Rs. 7200. Find the compound interest for the same period and rate.
  • A. Rs. 3502.80
  • B. Rs. 3052.40
  • C. Rs. 3054.80
  • D. Rs. 3052.80
Correct Answer: D
Explanation:
Rate = 12%, apply the compound interest formula.
Related Question 4
The simple interest on Rs. 49500 for 3 years is Rs. 17820. What is the compound interest on the same sum and time at the same rate?
  • A. Rs. 20043.94
  • B. Rs. 18654.81
  • C. Rs. 20264.46
  • D. Rs. 19612.41
Correct Answer: A
Explanation:
First, find the rate from SI, then apply the CI formula to get Rs. 20043.94.
Related Question 5
If the difference between compound and simple interest for 2 years is Rs. 50 on Rs. 1000, find the rate?
  • A. 5%
  • B. 10%
  • C. 7%
  • D. 8%
Correct Answer: A
Explanation:
Difference = P(R/100)² → R = 5%.