A certain sum of money amounts to Rs. 2200 at 5% p.a. rate

Home » Aptitude » Simple interest » Question

A certain sum of money amounts to Rs. 2200 at 5% p.a. rate of interest, Rs. 2320 at 8% interest in the same period of time. The period of time is :

Let Principal = Rs. P and time = T years
Rate = 5%

∴ SI =	Principal × Time × Rate
	100

According to the question,

∴ P +	PT × 5	= 2200
	100

&rArr4; P +	PT	= 2200...........(i)
	100

Again,	PT × 8	-	PT × 5	= 2320 – 2200
	100		100

⇒	3PT	= 120
	100

⇒ PT =	120 × 100	= 4000............(ii)
	3

∴ From equation (i),

P +	4000	= 2200
	20

⇒ P = 2200 – 200 = Rs. 2000
∴ From equation (ii),
PT = 4000

⇒ T =	4000	= 2 Year
	2000

Second method to solve this question :
Difference in rates = 8 – 5 = 3%
∵ 3% = 2320 – 2200 = 120

∴ 5% ≡	120	× 5 = 200
	3

∴ Principal = Rs. (2200 – 200) = Rs. 2000

∴ Time =	200 × 100	= 2 Years
	2000 × 5