Question

A sum of money amounts to RS 780 in two years and RS 1230in seven years. Find the principal and rate of simple interest

Answer 1

 

Let the amount be Rs x and rate of interest is r%

then (x+x*r*2/100) = 780....(1)

and x+x*r*7/100 = 1230...(2)

subtracting 2 from 1

then 5xr/100 = 450

or, xr = 9000

then x+180=780

hence pricipal amount is Rs 600 and rate of interest is15%