A man has rs.1900. He lent some of it at 5% pa and rest at 9% pa. The total amount of interest he got after 4 yrs was rs.580.What was the sum?

2 Answers
Jul 31, 2018

Amount lent @ 9% Interest = Rs 1250 and amount lent at 5% Interest = Rs 650.

Explanation:

Taking it as simple Interest:

I=PNR100

Let x be the amount lent @ 9% Interest.

Then 1900 - x is the amount lent at 5% Interest.

I=Rs580,N=4years

x49100+(1900x)45100=580

36x+3800020x=58000

16x=5800038000=20000

x=2000016=Rs1250

1900x=19001250=Rs650

Jul 31, 2018

Amount lent @ 9% Interest = Rs 869.71 and amount lent @ 5% is = Rs 1030.29

Explanation:

Taking it as compound interest.

A=P(1+R100)

Let x be the amount lent at 9% Interest.

Then 1900 - x is the amount lent @ 5% Interest.

P=1900,I=580,N=4years

1900+580=x(1+9100)4+(1900x)(1+5100)4

x1.094+19001.054x1.054=2480

1.4116x1.2155x=248019001.2155=170.55

x=170.551.41161.2155=869.71

1900x=1900869.71=1030.29