Question

A sum of money lent out at simple interest amount to rs. 720 after 2years and rs. 1020 after further period of 5 years. The sum is​

Answer 1

Principal + SI for 2 years = 720 Rs. ……(I)

Principal + SI for 7 years = 1020 Rs. ……(II)

Subtracting equation (I) from (II),

S.I. for 5 years = (1020 – 720) = 300 Rs.

∴ S.I. for 2 years = 300\times \frac{2}{5} = 120 Rs.

∴ Principal = (720 – 120) = 600 Rs.