If Simple Interest is 12.5% more than the principal and number of years(n), rate(r) are numerically in the ratio 2 : 1, then find the values of n, r.
n=20, r=10%
n=14; r=7%
n=12, r=6%
n=15; r=7\( \frac{1}{2} \)%
D. n=15; r=7\( \frac{1}{2} \)%