WBCS Mains 2020 Official Paper-VI

The compound interest on $\text{Rs. }10,000$ in $2\frac{1}{2}$ years at $10\%$ per annum is:

If $a=2021$, $b=2022$, and $c=2023$, then the value of $a^3+b^3+c^3-3abc$ is:

The marked price of a pen is $\text{Rs. }200$ and a customer buys it for $\text{Rs. }153$ after two successive discounts. If the first discount is $10\%$, then the second discount is:

If $\alpha$ and $\beta$ are the roots of the quadratic equation $a{x}^2+2bx+c=0$ and $\alpha +\gamma$, $\beta +\gamma$ are the roots of $A{x}^2+2Bx+C=0$, then which one of the following is correct?

A bus travels from Kolkata to Digha at the rate of $55\text{km/hour}$ and returns at the rate of $66\text{km/hour}$. Then the average rate of the whole journey is: