A sum of Rs. 7000 is invested in a scheme of simple interest. The rate of interest in this scheme is 20 percent per annum. If Rs. 1750 interest is obtained, then for how many months is the sum invested?

Correct option is C

Given:
Principal = Rs. 7000
Simple Interest obtained = Rs. 1750
Rate of interest = 20% per annum
Formula Used:
Simple Interest (SI) = $$\frac{\text{Principal} \times \text{Rate} \times \text{Time}}{100}$$​
Solution:
Time = $$\frac{1750 \times 100} {7000 \times 20} = 1.25 \text{years}$$​​
Convert to months:
Months = 1.25 $$\times$$​ 12 = 15 months
Thus, the sum is invested for 15 months.