Question

A sum doubles itself in 8 years at simple interest. Find the rate of interest per annum.
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Answer 1

Answer:

12.5 %

Step-by-step explanation:

let P= x

T= 8 years

Simple interest= 2P≈ 2x

R=?

Simple interest= P X R X T ÷ 100

2x= x X R X 8 ÷ 100

2x÷x= R X 8 ÷ 100

1= 2R÷ 25

1 X 25÷ 2= R

R= 12.5% per annum