Simple interest on a certain sum is 16/25 of the sum. Find the rate percent & time, if both are equal.

Question: Simple interest on a certain sum is 16/25 of the sum. What is the rate percent & time, if both are equal.

Solution:
Let.
The sum, P = Tk. x
Then, Simple interest, I = 16x/25
Rate of interest = r%
Since, rate percent = time
So r = n

We know,
I = Pnr
⇒ 16x/25 = x × r × r%
⇒ xr²/100 = 16x/25
⇒ r²/100 = 16/25
⇒ r² = 1600/25
⇒ r = 40/5
∴ r = 8

∴ Rate = 8% and Time = 8 years.