The amount of a certain sum at simple interest at 8% per annum in 7 1/2 years is ₹3,000 less than twice the sum. The sum (in ₹) is:

The amount of a certain sum at simple interest at 8% per…

The amount of a certain sum at simple interest at 8% per annum in 7 $\frac{1}{2}$ years is ₹3,000 less than twice the sum. The sum (in ₹) is:

Show answer & explanation

Correct answer: B

Explanation

The correct answer is Option 2 i.e. 7,500.

Let the sum be x

SI = $PRT\over100$

SI = $x\times 8\times15\over200$ = $6x\over10$

Amount(A) = x + SI = x + $6x\over10$ = $16x\over10$

Amount = 2x - 3000

⇒ $16x\over10$ = 2x - 3000

⇒ 2x - $16x\over10$ = 3000

⇒ $20x-16x\over10$ = 3000

⇒ $4x\over10$ = 3000

⇒ x = 7500