How many years will it take for an amount of Rs.400 to yield Rs.450 as interest at 5% per annum on simple interest?

Correct option is C

Given:
Principal, P = Rs.400, Interest = Rs.450, Rate, R = 5%.

Formula Used:
Simple Interest = $$\frac {P \times R \times T}{100}$$​ 

Solution:

$$450 = \frac {400 \times 5 \times T}{100} \\ \ \\ \implies 450 = 20T\\ \ \\ \implies T = \frac{450}{20} = 22.5.$$ 

Thus, Time is 22.5 years