CAT (QA) PYQs

The strength of a salt solution is $\mathrm{p} \%$ if $100 \mathrm{ml}$ of the solution contains $p$ grams of salt. Each of three vessels $\mathrm{A}, \mathrm{B}, \mathrm{C}$ contains $500 \mathrm{ml}$ of salt solution of strengths $10 \%, 22 \%$, and $32 \%$, respectively. Now, $100 \mathrm{ml}$ of the solution in vessel A is transferred to vessel B. Then, $100 \mathrm{ml}$ of the solution in vessel $B$ is transferred to vessel $C$. Finally, $100 \mathrm{ml}$ of the solution in vessel $C$ is transferred to vessel $A$. The strength, in percentage, of the resulting solution in vessel $A$ is

A $20 \%$ ethanol solution is mixed with another ethanol solution, say, $S$ of unknown concentration in the proportion $1:3$ by volume. This mixture is then mixed with an equal volume of $20 \%$ ethanol solution. If the resultant mixture is a $31.25 \%$ ethanol solution, then the unknown concentration of $S$ is

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