The simple interest on a sum of money is four-ninths of the principal. What will be the annual rate of interest and the time in years, if both of these are numerically equal?

A6 percent and 6 years

B6.8 percent and 6.8 years

CSix and a half percent and six and a half years

DSix and two thirds percent and six and two thirds years ✓ Correct

Correct answer: (D) Six and two thirds percent and six and two thirds years

Explanation

Both the rate and the time equal 6 and 2/3.

SI = (4/9)P and rate = time.

(4/9)P = P x r x r / 100.

r^2 = 400/9.

r = 20/3 = 6 and 2/3.

so rate = 6 and 2/3 percent and time = 6 and 2/3 years.

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