Question

The difference of SI and CI is 72 at 12% for 2 years. Calculate the amount

Answer 1

Answer:

If the difference between compound and simple interest is of two years than,

Difference = P(R)²/(100)²

Where P = principal amount, R = rate of interest

If the difference between compound and simple interest is of three years than,

Difference = 3 x P(R)²/(100)² + P (R/100)³.

Here also, P = principal amount, R = rate of interest

Test yourself by answering these 25 Practice Questions set of SI an CI.

Solved Examples

Q. The difference between the compound and simple interest on a certain sum at 12% per annum for two years is Rs. 90. What will be the value of the amount at the end of 3 years if compounded annually?

Ans: Here, in this question, the difference is already given to us and we are required to find the principal amount. And using that principal amount we are required to find the amount compounded after three years. The difference is given for two years. So, the formula will be,

Difference = P(R)²/100²

Now, putting the values into the equation, we will find that,

90 = P(12)²/(100)²

90 x 100²/12² = P

P = Rs. 6250

Now, calculating the compound interest on Rs. 6250 will be,

A = 6250(1 + 12/100)³

A = 6250(112/100)³ => 6250(1.12)³ => Rs. 8780.80

So, the compounded amount after three years will be Rs. 8780.80