Question

How much time will it take for an amount of rs. 450 to yield rs. 81as interest at 4.5% per annum of simple interest?

Answer 1

simple interst = PTR/100

Given that interest for time T is 81rs on 450rs of P at the rate of 4.5% annual rate of interest.

81 = (450 × T × 4.5)/100

81 × 100 = 2025 ×T

T = 81 × 100 / 2025

T = 8100/2025

T = 4 years.........

therefore, time taken is 4 years...............

Answer 2

The simple interest formula is given as follows :

Simple interest = Principle × rate/100 × Time in years.

We can write this as follows P:

SI = p × r/100 × t

P = 450

SI = 81

r/100 = 4.5/100 = 0.045

Doing the substitution we have :

81 = 450 × 0.045 × t

We are looking for t.

81 = 20.25t

t = 81/20.25

= 4

The time is 4 years.