CAT (QA) PYQs

The strength of a salt solution is $p\%$ if $100 \mathrm{ml}$ of the solution contains p grams of salt. If three salt solutions $A, B, C$ are mixed in the proportion $1: 2: 3$, then the resulting solution has strength $20 \%$. If instead the proportion is $3: 2: 1$, then the resulting solution has strength $30 \%$. A fourth solution, $D$, is produced by mixing $B$ and $C$ in the ratio $2: 7$. The ratio of the strength of $D$ to that of $A$ is

If a certain weight of an alloy of silver and copper is mixed with $3$ kg of pure silver, the resulting alloy will have $90\%$ silver by weight. If the same weight of the initial alloy is mixed with $2$ kg of another alloy which has $90\%$ silver by weight, the resulting alloy will have $84\%$ silver by weight. Then, the weight of the initial alloy, in kg, is

Anil mixes cocoa with sugar in the ratio $3: 2$ to prepare mixture $A$, and coffee with sugar in the ratio $7: 3$ to prepare mixture $B$. He combines mixtures $A$ and $B$ in the ratio $2: 3$ to make a new mixture $C$. If he mixes $C$ with an equal amount of milk to make a drink, then the percentage of sugar in this drink will be