WBCS Mains 2020 Official Paper-VI

Rahul's salary is first increased by $10\%$ and then again by $20\%$. But due to COVID-19, the salary is decreased by $25\%$. By what percent does the initial salary change?

A man buys two types of oranges equal in number, one at $5$ for a rupee and the other at $3$ for a rupee, and sells the entire lot at $6$ for $\text{Rs. }2$. His gain or loss percent is:

A train travels at a speed of $30\text{km/hour}$ for $12$ minutes and then for the next $8$ minutes at a speed of $45\text{km/hour}$. The average speed for the entire journey is:

If $\tan 2\theta \tan \theta =1$, then the value of $\tan 2\theta$ is:

$\Delta ABC$ is a triangle where $\angle C=90^{\circ }$. If $p$ is the length of the perpendicular from $C$ to $AB$, then $\frac{1}{B{C}^2}+\frac{1}{A{C}^2}=$