Question

A sum of money at simple interest amounts to 800 in 2 years and to 1200 in 6 years. The sum is

• A. 600
• B. 1000
• C. 400
• D. 500

Answer 1

The correct option is A 600

Simple Interest $SI=\frac{PNR}{100}$
Given,
$AmountA=800$
$=>P+SI=800$
$=>P+\frac{P\times 2\times R}{100}=800$
$=>P(100+2R)=80,000$ -- (2)
And $AmountA=1200$
$=>P+SI=1200$
$=>P+\frac{P\times 6\times R}{100}=1200$
$=>P(100+6R)=120000$ - (2)
Dividing eqn 2 by 1, we get
$\frac{100+6R}{100+2R}=\frac{12}{8}$
$=>R=\frac{100}{6}$ %
Substituting in eqn 2, we get
$P=Rs600$