Question

At what percent rate per annum simple interest will be a sum of money three times / in 25

years?

Answer 1

We know that

SI = P * R * T
Thus when Money is made three times

3 * SI = P * R' * 25

Thus
Solving above equations
we get

R = 3/4
    = 0.75 
Thus
Rate will be 75%

Answer 2

Solution :-

Let the Principal be Rs. 100

Then, the simple interest will be Rs. 300

Now, according to the question.

⇒ S.I. = (P*R*T)/100

⇒ 300 = (100*R*25)/100

⇒ 300 = 2500R/100

⇒ 2500R = 30000

⇒ R = 30000/2500

⇒ R = 12 %

So, the interest rate is 12 % per annum

Answer.