Question

Find the sum that amounts to Rs 9,144 in 3 years at 9% per year simple interest.​

Answer 1

Given:

Amount = Rs. 9,144

Time = 3 years.

Rate of simple interest = 9%

To find:

The principal value.

Solution:

The formula for simple interest is:

`I=(P* r* t)/(100)`

Where, P is principal, r is the simple rate of interest, and t is the number of years.

Putting
`r=9,t=3` in the above formula, we get

`I=(P* 9* 3)/(100)`

`I=(27P)/(100)`

`I=0.27P`

We know that,

`\text{Amount}=\text{Principal + Interest}`

`9144=P+0.27P`

`9144=1.27P`

Divide both sides by 1.27, we get

`(9144)/(1.27)=P`

`7200=P`

Therefore, the principal value is Rs. 7200.