The simple interest on a certain sum is one-eighth of the sum when the number of years is equal to half of the rate percentage per annum. Find the simple interest (in ₹) on ₹15,000 at the same rate of simple interest for 8 years.

6,000

Simple Interest(S.I.)=\(\frac{P×R×T}{100}\) 

Let P = 8. then S.I. = 1

Rate of Int. = \(\frac{1}{8}\) × 100 = \(\frac{25}{2}\)%

Total Rate of Int. = Rate × Time

                         = R × \(\frac{R}{2}\)                      (Time is half of rate)

\(\frac{25}{2}\) = \(\frac{R^2}{2}\)

R² = 25

R = 5%

Total Interest for 8 years  = 5 × 8 = 40%

Final S.I. = 15000 × \(\frac{40}{100}\) = 6000 Rs