Question

On a certain sum of money, invested at the rate of 5% per annum compounded annually, the difference between the interest of the first year and the interest of the third year is rs.61.50.Find the sum.​

Answer 1

✭Required✭

• Let the principal= rs.100

C.I. for 1st year = (100×5×1)/100= rs.5

Amount of 1st year=100+5=rs.105

✭Principal for 2nd year=rs.105

C.I. for 2nd year=(105×5×1)/100= rs.5.25

Amount for 2nd year=105+5.25= rs.110.25

✭Principal for 3rd year=rs.110.25

C.I. for 3rd year=(110.25×5×1)/100= rs.5.51

• Difference between C.I. of 1st year and 3rd year= 5.51-5=0.51

Now, when the difference on interest= rs.0.51 and principal=100

A.T.Q.

When difference of interest=rs.61.50

➡P=100/0.51×61.50=12000

✭So the Principal is rs.12000✭

♡Hope it helps you....