A man invests some money partly in 9% stock at 96 and partly in 12% stock at 120. To obtain equal dividends from both, he must invest the money in the ratio:

Answer: Option D

For an income of Rs. 1 in 9% stock at 96, investment =
$$Rs.\left(\frac{96}{9}\right)=Rs.\frac{32}{3}$$
For an income Rs. 1 in 12% stock at 120, investment =
$$Rs.\left(\frac{120}{12}\right)=Rs.10$$
∴ Ratio of investments
= $$\frac{32}{3}$$ : 10
= 32 : 30
= 16 : 15