Question

in what time will the simple interest on a certain sum be 3/4 of the principal at 6% per annum

Answer 1

let principal be p
as the intrest is 3/4 of p
so intrest = 3/4p
$t = \frac{i \times 100}{p \times r} \\ t = \frac{3p \times 100}{4 \times p \times 6} \\ t = 12.5$