THE DIFFERENCE BETWEEN THE COMPUND INTERST AND SIMPLE INTERST ON A CERTAIN SUM FOR 2 YEARS AT 6%PER ANNUM IS RS 90 . FIND THE SUM .

let the sum of money be p

for simple interest, interest = p(.06)(2) = .12p
for compound interest, interest = p(1.06)^2 - p

p(1.06)^2 - p - .12p = 90
p( 1.06^2 - 1 - .12) = 90
solve for p

let me know what you got