Question

at what rate per cent per annum will a sum of money double itself in 5 years​

Answer 1

Answer:

The shorthand rule of 72 is great quick mental tool. If you divide 72 by an interest rate, you get the number years it would take to double. If you divide 72 by the number of years, you get the the rough interest rate required to double. So 72/5 = 14.4 years. It is not exact, but a good ballpark figure. And if you are talking about “doublings” that is really all you are doing, ballparking