Question

at what rate of interest a certain sum will be doubled in 8years? Ans fast pls.

Answer 1

Let the Principle(P) be Rs x.
∴ Amount (A)= Rs 2x

Simple Interest (SI) = A - P
                               = 2x - x
                               = x
Time (T) = 8 yrs.

Rate (R) = 100*SI / P*T
               = 100*x / x*8
               = 25/2
               = 12.5%

12.5% is your answer.

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