Question

$A$ borrows Rs.$800$ at the rate of $12\%$ per annum simple interest and$B$ borrows Rs.$910$ at the rate of $10\%$ per annum, simple interest. In how many years will their amounts of debt be equal?

• A. $18years$
• B. $20years$
• C. $22years$
• D. $24years$

Answer 1

The correct option is C

$22years$

Let us consider after $t$year amount is equal.

Consider an equation.

$800+\frac{800\times 12\times t}{100}=910+\frac{910\times 10\times t}{100}$

⇒ $800+96t=910+91t$

⇒$5t=110$

⇒ $t=22years$

Hence After $22years$ the amount will be equal.