Q23
On a certain sum of money the compound interest for 2 years is Rs. 282.15 and the simple interest for the same period of time is Rs. 270. The rate of interest per annum is = ?
A.
6.07%
B.
10%
C.
9%
AnswerD.
12.15%
Answer: Option C
Solution
Answer: Option C
Solution:
\begin{aligned}
& {\text{CI for 2 years}}\,{\text{ = Rs. 282}}{\text{.15}} \\
& {\text{SI for 2 year}}\,{\text{ = Rs. 270}} \\
& {\text{SI for 1 year = }}\frac{{270}}{2} \\
& \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = {\text{Rs.}}\,135 \\
& {\text{Difference between CI and SI}} \\
& {\text{ = }}\left( {282.15 - 270} \right) \\
& {\text{ = Rs. 12}}{\text{.15}} \\
& {\text{Required rate % }} \\
& {\text{ = }}\frac{{12.15}}{{135}} \times 100 = 9\% \\\end{aligned}Note : Always remainder for first year CI and SI will be same.