A man invested 3400 in simple interest at 12% p.a. for (x+1) years. If the interest received by him is 3/5th the amount invested, then find x.

Correct option is B

ATQ,
$$3400 \times \frac{3}{5} = 3400 \times \frac{12}{100} \times (x + 1)$$​
$$\frac{3}{5} = \frac{12}{100} \times (x + 1)$$​
5 = x + 1
x = 4