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

Competition practiceSimple & Compound Interest
  • A12.5
  • B8
  • C10
  • D15

Step-by-Step Solution

To double, the interest equals the principal, so 8 = 100, giving % per annum.
Answer: A) 12.5

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