If $Rs. 10$ is allowed as true discount on a bill of $Rs. 110$ due at the end of a certain time,then the discount allowed on the same amount due at the end of double the time is (in $Rs.$)

What rate of interest does a man get for his money when in discounting a bill due in $10 \, \text{months}$, he deducts $4 \%$ of the amount of the bill? (in $\%$)

If the true discount on $Rs. 161$ due for $2$ years and $6$ months is $Rs. 21$, then find the rate of interest (in $\%$).

$A$ bill for $Rs. 8000$ is drawn on September $19$ for $6$ months. It is discounted on January $8$ at $10\%$. Find the banker's discount,true discount,banker's gain,and the money that the holder of the bill receives (in $Rs.$).

At $20 \%$ discount,the selling price of an article is $Rs. 2400$. What is the selling price (in $Rs.$) if the discount is $32.5 \%$?

The banker's discount on $Rs. 2400$ at $12 \%$ p.a. is the same as the true discount on $Rs. 2520$ for the same time and at the same rate. The time is (in months):