Question

What sum of money will amount to $Rs.520$ in $5$ years and to $Rs.568$ in $7$ years at simple interest?

• A. (a)$Rs.400$
• B. (b)$Rs.120$
• C. (c)$Rs.510$
• D. (d)$Rs.220$

Answer 1

The correct option is A (a)$Rs.400$

Interest for two years $=Rs.568-Rs.520=Rs.48$
$\therefore S.I.for1year=Rs.\frac{48}{2}=Rs.24$
$\therefore S.I.for5years=5\times Rs.24=Rs.120$
$\therefore$ Principal $=Amount-S.I.$
$=Rs.520-Rs.120=Rs.400$.