Q60
There is 60% increase in an amount in 6 years at simple interest. What will be the compound interest of Rs. 12000 after 3 years at the same rate ?
A.
Rs. 2160
B.
Rs. 3120
C.
Rs. 3972
AnswerD.
Rs. 6240
E.
None of these
Answer: Option C
Solution
Answer: Option C
Solution:
\begin{aligned}
& {\text{Let P}} = {\text{Rs}}.100 \\
& {\text{Then,}} \\
& {\text{S}}{\text{.I}}{\text{. = Rs}}.60{\text{ and}} \\
& {\text{T = 6 years}} \\
& {\text{R = }}\frac{{100 \times 60}}{{100 \times 6}}{\text{ = 10% p}}{\text{.a}}{\text{.}} \\
& {\text{Now}} \\
& {\text{P = Rs 12000,}} \\
& {\text{T = 3 years and}} \\
& {\text{R = 10% p}}{\text{.a}}{\text{.}} \\
& \therefore {\text{C}}{\text{.I}}{\text{. = Rs}}{\text{.}}\left[ {12000 \times \left\{ {{{\left( {1 + \frac{{10}}{{100}}} \right)}^3} - 1} \right\}} \right] \\
& = {\text{Rs}}{\text{.}}\left( {12000 \times \frac{{331}}{{1000}}} \right) \\
& = {\text{Rs}}{\text{. }}3972 \\\end{aligned}