In how many years will a sum of money be doubled itself at a simple interest of 10% p.a.?

Correct option is C

To determine the number of years required for a sum of money to double at 10% per annum simple interest, we use the simple interest formula:

SI = (P × R × T) / 100

where:

• SI is the simple interest,
• P is the principal amount,
• R is the rate of interest per annum,
• T is the time in years.

Since the amount doubles, the simple interest must be equal to the principal (i.e., SI = P). Substituting this into the formula:

P = (P × 10 × T) / 100

Canceling P from both sides:

1 = (10 × T) / 100

Multiplying both sides by 100:

100 = 10T

Solving for T:

T = 100 / 10 = 10 years

So, the sum of money will double in 10 years at a simple interest rate of 10% per annum.