Question

A sum of money will double itself in 16 years at simple interest with yearly rate of

Answer 1

The money doubles itself, it means 100% money is added.

So,
Interest × Time = 100%
Interest × 16 = 100
Interest = 100/16
Interest = 6.25

So the simple interest is 6.25% per year.

Hope it helps.

Answer 2

As money will increase the sum is 100% which will add to the amount

Principal = P

Time = 16 years

Simple Interest  is

I x Time = 100%

I x 16 = 100

I = 100/16

Interest = 6.25%