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:

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