revital wrote:

If a sum of money grows to 144/121 times when invested for two years in a scheme where interest is compounded annually, how long will the same sum of money take to treble if invested at the same rate of interest in a scheme where interest is computed using simple interest method? (1) 9 years (2) 22 years (3) 18 years (4) 33 years

Correct Answer - (2)

I got 22, also. If the interest squared times the original is 144/121, then the interest is 12/11, which means the actual interest is 1/11. so you want to triple the principle by figuring out how many times you should add the product of itself and 1/11 to itself. Meaning, the final equation I got would be p + x([1/11]p) = 3p, and solving for x --> x=22