What sum will amount to Rs. 7000 in 5 years at 31/3 % simple interest ?

Answer: Option C

$$\begin{array}{rl}& \text{Amount Rs 7000}\\ & \text{Total interest in 5 years}\\ & \text{ = 5}\times \frac{10}{3}\%=\frac{50}{3}\%=\frac{1}{6}\end{array}$$

Principal	Amount
6	(6 + 1)
↓ × 1000	↓ × 1000
6000	7000

Hence required principal = Rs. 6000