The difference between the simple interest and the true

Home » Aptitude » True Discount » Question

The difference between the simple interest and the true discount on a certain sum of money for 2 years at 15 % per annum at simple interest is ₹45. Find the sum.

Let the sum be ₹100.
Given that :- Time = 2 years
Rate = 15% per annum

Simple Interest = ₹		100 × 15 × 2		= ₹30
		100

True Discount = ₹		100 × R × T
		100 + (R×T)

True Discount = ₹		100 × 15 × 2
		100 + (15×2)

True Discount = ₹		100 × 15 × 2		= ₹	300
		100 + (15×2)			13

The difference between Simple Interest and True Discount is

₹		30 -	300		= ₹	90
			13			13

If the difference in S.I. and True Discount is ₹	90	,the sum = ₹100
	13

If the difference in S.I. and T.D. is ₹1,

The sum = ₹100 x	13	.
	10

If the difference in S.I. and T.D. is ₹45,

The sum = ₹100 ×	13	× 45 = ₹650.
	90