Simple Interest - General Aptitude

Q1:

A lent Rs. 5000 to B for 2 years and Rs. 3000 to C for 4 years on simple interest at the same rate of interest and received Rs. 2200 in all from both of them as interest. The rate of interest per annum is:

A 5%

B 7%

C 71%8

D 10%

ANS:D - 10%

Let the rate be R% p.a.

Then, 5000 x R x 2 + 3000 x R x 4 = 2200.
100 100
 100R + 120R = 2200
 R = 2200 = 10.
220
 Rate = 10%.