Question

The difference in S.I. and C.I. on a certain sum of money in 2 years at $15\%$ p.a. is ₹144. The sum is .

• A. ₹6000
• B. ₹6800
• C. ₹6400

Answer 1

The correct option is C ₹6400

C.I. - S.I. = ₹144
$P\{{(1+\frac{R}{100})}^n-1\}-\frac{PRT}{100}=144$
$P\{{(1+\frac{15}{100})}^2-1\}-\frac{P\times 2\times 15}{100}=144$
$P\{{(1+\frac{3}{20})}^2-1\}-\frac{P\times 30}{100}=144$
$P\{{\left(\frac{23}{20}\right)}^2-1\}-\frac{P\times 30}{100}=144$
$P\{\left(\frac{529}{400}\right)-1\}-\frac{3\times P}{10}=144$
$P[\frac{129}{400}-\frac{3}{10}]=144$
$P\left[\frac{9}{400}\right]=144$
$P=\frac{144\times 400}{9}$
$=₹6400$