Question

the simple interest on a sum of money is equal to the principal and the number of years is equal to the rate % per annum. find the rate %

Answer 1

According to this Question,

$s = \frac{p \times r \times t}{100} \\ p = \frac{p \times r \times r}{100} \\ \frac{p}{p} = \frac{ {r}^{2} }{100} \\ 1 = \frac{ {r}^{2} }{100} \\ 100 = {r}^{2} \\ \sqrt{100} = r \\ r = 10$

Rate is 10%