Group D (4x5=20)

34. A sum of money amounts to Rs. 19361 in 2 years and Rs. 23425.60in

4 years at the rate of compound interest annually. Find the rate of

compound interest and the sum.

rate of compound interest: 10%

the sum: Rs. 16000.83

Step-by-step explanation:

compound interest: A = P (1 + r) ⁿ P: initial sum r: annual interest n: period

23425.60 = P (1 + r) ⁴ (a)

19361 = P (1 + r) ² (b)

A/b: 23425.60 / 19361 = (1 + r) ²

(1 + r) ² = 1.21

1 + r = 1.1

r = 0.1 (10%)

P = 19361 / 1,21 = 16000.83