A sum of Rs.800 becomes Rs.956 in 3 years at some rate of Simple Interest. If the rate is increased by 4%, then what will be the gain in the investment?

Correct option is B

Given:

Principal (P): ₹800

Amount after 3 years (A): ₹956

Time (T): 3 years     

Formula Used:   

SI = $$\frac{P \times R\times T}{100}$$

Solution:

Let the rate be R%

Interest = 956 – 800 = 156
As we know,
​$$SI =\frac{ (P×R×T)}{100} \\\ \\156 = \frac{(800×R×3)}{100} \\\ \\R =\frac{ (100×156)}{(800×3)}=6.5$$​​
Rate increased by 4%
Then R = 6.5 + 4 = 10.5
SI  = 252$$\frac{(800×10.5×3)}{100} = 252$$​​
Thus, gain in investment = 252 – 156 = 96.