Question

A sum of money becomes Rs. 20925 in 2 years and Rs. 24412.50 in 5 years. Find the rate of interest and the sum of money

Answer 1

I think the answer is50748

Answer 2

Let the sum of money, Principal = P
Let the rate = R
Let time = T

Amount, A = P + PRT/100

In 2 years
20925 =  P + 2PR/100
20925 = P + PR/50  ….. (i)

In 5 years
24412.50 = P + 5PR/100
24412.50 = P + PR/20 …(ii)

Solving (i) and (ii) simultaneously,
Multiply (i) by 50 and (ii) by 20

1046250 = 50P + PR …….. (iv)
488250 = 20P + PR …….(v)

Subtract (v) from (iv)
558000 = 30P
P = 558000/30 = 18600

From (i)
20925 = P + PR/50  ….. (i)

20925 = 18600 + 18600R/50

20925 – 18600 = 372R

2325 = 372R

R = 2325/372

R = 6.25
Therefore;The sum of money, Pricipal = Rs. 18600
Rate of interest, R = 6.25%