Question

On a certain sum, the compound interest in 2 years amounts to Rs 4240. If rates of interest for successive years are 10% and 15% respectively, find the sum.(using formula)

Answer 1

The answer is ₹16000. The solution is given in the picture.

Answer 2

Use the formula for successive percentage, a+b+a.b/100 hence resultant rate will be 10+15+1.5=26.5. Now we know the CI=4240, R=26.5% hence calculate using formula.

P(1+26.5/100)^2 -P = 4280, hence P = 16000.