Question

19. A person gets 200 more interest by investing
20,000 at R% p.a. compound interest instead of
simple interest for two years then R is
%​

Answer 1

Solution :-

→ Principal = Rs.20,000

→ Let Rate = R% per annum.

→ Time = 2 years.

→ More ineterest gets in CI than SI for 2 years = Rs.3200

using formula for Diff. b/w CI and SI for 2 years = (Principal * (Rate)²) / (100)²

Putting all values we get,

→ 3200 = (20000 * R²) / (100 * 100)

→ 3200 = (20000 * R²) / (10000)

→ 3200 = 2R²

→ R² = 1600

→ R² = 40²

→ R = 40% Per Annum. (Ans.)