Question

in how many years will a sum of mony become double at 5% per annum

want full solution​

Answer 1

When we replace r with 0.05 (5%), we find t=14.2067, which means that applying an interest rate of 5% per year, the initial amount will double in 14.2067 years, or 14 years and almost 2 and a half months (2.48 to be exact).

Answer 2

Answer:

Let Principal be P. Rate of interest = 5%

Assuming Simple Interest,

SI = P {since the money doubles}

P X T X 5/100 = P

T = 100/5 = 20 years

Assuming annually compounded interest ,

P (1+5/100)T = 2P

(1.05)T = 2

T is between 14 to 15 years.

If T = 14 years, the principal is a bit less than double, hence approximately T = 15 years.