The difference between the simple and compound interest

The difference between the simple and compound interest on a certain sum of money at 5% rate of interest per annum for 2 years is ₹ 15. Then the sum is :

Here , Difference = C.I. - S.I.= ₹ 15 , Time = 2 years , Rate = 5%
Let the sum P. Then,

C.I. = P		1 +	5		²	− P
			100

C.I. =	441P	− P =	441x − 400P
	400		400

C.I. =	41	P
	400

Now,

S.I. =	P × 5 × 2	=	P
	100		10

∴ (C.I.) – (S.I.) =	41P	−	P
	400		10

C.I. – S.I. =	41P − 40P	=	P
	400		400

∴	P	= 15
	400

⇒ P = 15 × 400 = 6000
Hence, the sum is ₹ 6000
Second Method to solve this question :
C.I. – S.I. = ₹ 15, R = 5%, T = 2 years, P = ?

C.I. − S.I. = P		R		²
		100

15 = P		5		²
		100

P = 15 × 400
P = ₹ 6000