CAT (QA) PYQs

How many two-digit numbers, with a non-zero digit in the units place, are there which are more than thrice the number formed by interchanging the positions of its digits?

Let $m$ and $n$ be natural numbers such that $n$ is even and $0.2<\frac{\mathrm{m}}{20}, \frac{\mathrm{n}}{\mathrm{m}}, \frac{\mathrm{n}}{11}<0.5$. Then $m-2n$ equals

If $a$ and $b$ are integers such that $2x^2 - ax + 2 > 0$ and $x^2 −bx + 8 \geq 0$ for all real numbers $x,$ then the largest possible value of $2a-6b$ is