Question

a sum of money becomes 8÷5 of itself at a certain rate of simple interest. Fibd the rate if interest​

Answer 1

Answer:

Let the principal be P.

A/Q A = 8/5P

Given T=5years

WKT, SI = A-P

= 8P/5 -P

SI =3P/5

Again ,

SI =PRT/100

3P/5=PRT/100

3/5=5R/100

R=3*20/5

R=3*4

R=12.

Answer 2

$\huge\sf{Answer:-}$

• Let y be the pricipal amount.

• 5 years is the time given.

8y / 5

Hence

SI = Amount - Principal

SI = 8y / 5 - y = 3y / 5

SI = P × R × T / 100

= y × R × 5 / 100 = 3y / 5

= 5y × R = 3y × 100 / 5 = 60y

= R = 60y / 5y = 12%