Question

At what rate of simple interest will a sum treble itself in 20 years

Answer 1

time (T)= 16 years

Amount (A) = 3 * Principal (P)

As we know

Interest(I)=Amount - Principal

I=2*p

As you say sum tripled in 16 years then,

we know that

I = P*R*T/100

So, 2*P =P*R*16/100

R= 12.5%

So rate of percentage per annum must be 12.5% to triple the sum