Anuradha invests her money in a firm where the principal amount becomes 3 times in 10 years. What is the yearly rate of simple interest offered by the firm?

20%

Let Principle = Rs 100

Amount = 300 Rs

Time = 10 years

Interest  = 300 - 100 = 200 Rs

Interest for 10 Year = Rs 200

Interest for 1 year = Rs 20

∴ Rate=\(\frac{I}{P}\) × 100 = \(\frac{20}{100}\) × 100 = 20%