Question

8. A certain sum of money trebles itself in 8 years. In how many years will it be five times​

Answer 1

Assuming SIMPLE INTEREST,( the problem doesn’t STATE it is earning intetest, it could be any other form of gain, such as dividend on investment, or profit in a business venture etc., but any other mode introduces POSSIBLE VARIATIONS IN RETURNS FROM YEAR TO YEAR, while the query requires to compute time taken for reaching the five times amount based on the given data, implying it is NOT a variable rate, so safe to assume interest or another form of FIXED RETURN).The money is gaining 25% per year, thus 25*8=200 gain, treble amount. So for five times the amount, gain needed is 400%, 400/25=16 years.

if interest earned (or whatever was the means of gain)was compounded every year, the number of years for tripling the amount would not normally be a round 8 years figure, unless, of course, the rate of return is an awkward number running into several decimals between 14.7 and 14.8.

Answer 2

Mathematics is the science that deals with the logic of shape, quantity and arrangement. Math is all around us, in everything we do. It is the building block for everything in our daily lives, including mobile devices, architecture (ancient and modern), art, money, engineering, and even sports.