# What will be the Interest Rate? If

A sum of money becomes 5.5 times in 30 years at simple interest. Find the rate of interest?

- 10%
- 15%
- 12%
- 18%

**Answer: (2) 15 %**

**Explanation:-**

Let the rate be R % & principal is P

Given-

Time = 30 years, Amount = 5.5 times of principal = 5.5 P

Simple Interest = 5.5 P – P = 4.5 P

**Formula-**

**Simple Interest = P x R x T/100**

**Where, P = principal , R = rate, & T = time.**

Then, 4.5 P = P x R x 30/100

4.5 = 3 R/10

3 R = 4.5 x 10

3 R = 45

R = 45/3

R = 15 %

Then, the rate of interest is 15 %.

Hence, the answer is (2) 15 %.