CAT (QA) PYQs

A chemist mixes two liquids $1$ and $2$. One litre of liquid $1$ weighs $1 \mathrm{~kg}$ and one litre of liquid $2$ weighs $800 \mathrm{gm}$. If half litre of the mixture weighs $480 \mathrm{gm}$, then the percentage of liquid $1$ in the mixture, in terms of volume, is

There are four bottles. It is known that either one or two of these bottles contain(s)only P, while the remaining ones contain 85% P and 15% I. What is the minimum number of tests required to ascertain the exact number of bottles containing only P?

Two alcohol solutions, $A$ and $B$, are mixed in the proportion $1:3$ by volume. The volume of the mixture is then doubled by adding solution $A$ such that the resulting mixture has $72 \%$ alcohol. If solution $A$ has $60 \%$ alcohol, then the percentage of alcohol in solution $B$ is