A certain sum of money invested in compound interest grows to 1.77 times in two years. If the sum were invested in simple interest how long will it take for the sum of money to treble?

Explanation:

A=P(1+r\100)^n. Given that, A\P=1.77 and n=2 years

or 1.77 = (1+r\100)^2or√1.77=1+r100

or 1.33 -1 = r\100 or r = 33.3%

If the sum were to treble in SI, (SI = 2*P)

n = 200\r=200\33.33 = 6yrs

Therefore, it takes 6 years to treble.