Question

Chapter :- Simple InterestCalculate the sum which amounts to Rs. 808 in
`2 (1)/(2) \: years`at
`10 (1)/(2) \% \: p.a.`

Answer 1

To solve this question using simple interest, use the formula below.

`A=P(1+rt)`

Where:

A = Final amount.

P = Initia principal.

r = rate.

t = time.

In this exercise,

A = 808

P = to be found

r = 0.105

t = 2.5

Then, substituting the values:

`\begin{gathered} 808=P\cdot(1+0.105\cdot2.5) \\ 808=1.2625P \end{gathered}`

Dividing both sides by 1.2625:

`\begin{gathered} (808)/(1.2625)=(1.2625)/(1.2625)P \\ 640=P \end{gathered}`

Answer: the sum that amounts to 808 is 640.