Question

A sum of money becomes 1,331 times in 3 years as compound interest. The rate of interest is-

Options

• 8%

• 7.5%

• 10%

• 50%

Answer 1

10%

Explanation:

If principal = ₹1000, amount = ₹1331

∴ A = `"P" (1 + "R"/100)^"T"`

⇒ `1331/1000 = (1 + "R"/100)^3`

⇒ `(11/10)^3 = (1 + "R"/100)^3`

⇒ `1 + "R"/100 = 11/10`

⇒ `"R"/100 = 1/10`

⇒ `"R" = 1/10 xx 100`

= 10%