Question

Calculate the compound interest for the third year on Rs. $15,000$ invested for $5$ years at $10\%$ per annum.

• A. Rs. $1815$
• B. Rs. $1825$
• C. Rs. $1845$
• D. Rs. $1875$

Answer 1

Answer: (A)

Rs. $1815$

Here $P=$ Rs. $15,000,R=10\%$

C.I. for 2 years $=$ $P\times {(1+\frac{R}{100})}^2-P$ ......(1)

C.I. for 3 years $=$ $P\times {(1+\frac{R}{100})}^3-P$ ......(2)

By subtracting (1) from (2):

C.I. for third year $=$ C.I. for three years $-$ C.I. for two years $=P\times \frac{R}{100}\times {(1+\frac{R}{100})}^2$

C.I. for third year $=$ $15000\times \frac{10}{100}\times {(1+\frac{10}{100})}^2$

C.I. for third year $=$ $1500\times \frac{121}{100}$

C.I. for third year $=$ Rs. $1815$