Question

In what time will a sum amount of 5 times of itself at the rate of 7.5% per annum.​

Answer 1

Answer:

a) 53 years and 4 months

Step-by-step explanation:

Formula : Time = SI x 100/ ( rate x principal )

In our case, principal is y and SI is 4y so that the amount is 1y + 4y = 5y

So, Time = 4y x 100/ y x (75/10) = 400 x 10/ 75 = 160/3 = 53 1/3

1/3 years = 12 months/ 4 = 4  months