Question

in how many years will a sum of money become double at 5% p..a?​

Answer 1

Given ,

Principal = Rs. x ( assumed )

Rate of interest = 5% per anum

Amount = Rs. (2*x) = Rs. 2x

Therefore ,

Interest = Rs. (2x-x) = Rs. x

Let the time period be assumed as t years

We know ,

S.I. = (P*R*T)/100

=> x = (x*5*t)/100

=> x * 100 = (X* 5 * t)

=> 100x = 5x * t

=> t = 100x / 5x

=> t = 20 years

Answer :- The time period for the principal to double is 20 years .