Explanation:
Given : Sum of rupees 2400 Amount to rupees 4147.20 compounded annually for 3 years.
To Find : Rate percent per annum, R
Solution:
From the given statement :
Principal , P = ₹ 2400
Amount, A = ₹ 4147.20
Time period, n = 3 years
Using the formula,
A = P(1 + R/100)ⁿ
4147.20 = 2400 (1 + R/100)³
4147.20 / 2400 = (1 + R/100)³
172.8 / 100 = (1 + R/100)³
1.728 = (1 + R/100)³
(1 + R/100) = ³√1.728
1 + R/100 = 1.2
R/100 = 1.2 - 1
R/100 = 0.2
R = 0.2 × 100
R = 20 %
Rate percent per annum, R = 20%
Hence, the rate percent per annum is 20 %.