compound interest
2.  The difference between simple and compound interests compounded annually on a certain sum of money for 2 years at 4% per annum is Re. 1. The sum (in Rs.) is:  
Answer: Option A Explanation:
Let the sum be Rs. x. Then,
x = 625. 
3.  There is 60% increase in an amount in 6 years at simple interest. What will be the compound interest of Rs. 12,000 after 3 years at the same rate?  
Answer: Option C Explanation:
Let P = Rs. 100. Then, S.I. Rs. 60 and T = 6 years.
Now, P = Rs. 12000. T = 3 years and R = 10% p.a.

4.  What is the difference between the compound interests on Rs. 5000 for 1 years at 4% per annum compounded yearly and halfyearly?  
Answer: Option A Explanation:
Difference = Rs. (5306.04 – 5304) = Rs. 2.04 
5.  The compound interest on Rs. 30,000 at 7% per annum is Rs. 4347. The period (in years) is:  
Answer: Option A Explanation:
Amount = Rs. (30000 + 4347) = Rs. 34347. Let the time be n years.
n = 2 years. 