Question

in How many years will a sum of money becomes triple at 10% per annum simple interest?

Answer 1

I Think the answer is 20 years.
As the interest is 10% per annum.In one day the amount's 10% will be added.So for becoming the double amount is will take 10 year.Now the amount is doubled.Now again a 10 years.Now the amount is tripled.
So 10+10=20 years.

Answer 2

Simple interest is formulated as,

S.I.=$\frac{P*R*T}{100}$  

Here P signifies the principal amount, R signifies that the rate of interest and T signifies the time in yrs.

Now that we will need to triple the money, that is  

S.I.=3P  

So, substituting S.I.=3P  and R=10 in the formula, we get

3P=$\frac{P*10*T}{100}$Neglecting P, as it is in both the sides of the equation.

3×100=10T  

T=$\frac{300}{10}$=30 years  

Hence the time required is 30 years