In how many years will a sum of ₹1,600 amount to ₹2,116 at 15% compound interest?

Correct option is C

Given:

Principal (P) = ₹1,600
Amount (A) = ₹2,116
Rate (R) = 15% per annum
Time (n) = ? 

Formula Used:

​$$A = P \left(1 + \frac{R}{100}\right)^n$$​

Solution:

2116 =$$1600 \left(1 + \frac{15}{100} \right)^n$$​

2116 = 1600 $$(1.15)^n$$​

​$$\frac{2116}{1600} = (1.15)^n$$​

​$$1.3225 = (1.15)^n$$​

​$$(1.15)^2 = (1.15)^n$$​

So,

n = 2 years

Alternate Method:

Rate (R) = 15% =$$\frac{15}{100}=\frac{3}{20}$$

So, Time = 2 years