Question

The difference between the $S.I.$ and $C.I.$ obtained on principal amount at $5$ p.c.p.a. after $2$ years is $Rs35$ What is principal amount.

• A. $Rs15000$
• B. $Rs10000$
• C. $Rs14000$
• D. $Rs13000$

Answer 1

The correct option is C $Rs14000$

Difference between $CI$ & $SI=35Rs$

Simple Interest $=\frac{PRN}{100}=\frac{P\times 5\times 2}{100}=\frac{P}{10}$

Compound Interest $=P\left[\right(1+\frac{R}{100}{)}^N]-P$

$=P\left[\right(1+\frac{R}{100}{)}^N-1]$

$=P\left[\right(1+\frac{5}{100}{)}^2-1]$

$=P\left[\right(\frac{105}{100}{)}^2-1]$

$=P\left(0.1025\right)$

$\to CI-SI=35Rs$

$\therefore P\left(0.1025\right)-\frac{P}{10}=35$

$\therefore P(0.1025-0.1)=35$

$\therefore P=\frac{35}{0.0025}$

$\therefore P=14000Rs$