$A$ cloth merchant has announced a $25 \%$ rebate in prices. If one needs to have a rebate of $Rs. 40$,then how many metres of cloth costing $Rs. 32$ per metre should he purchase?

The banker's discount on a certain sum of money is $Rs. 84$ and the true discount on the same sum for the same time is $Rs. 70$. The sum due is (in $Rs.$)

If on a marked price,the difference between the selling prices with a single discount of $30 \%$ and two successive discounts of $20 \%$ and $10 \%$ is $Rs.\, 72$,then the marked price (in $rupees$) is:

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):

If the simple interest on $Rs. 2000$ at $5\%$ $p.a.$ is equal to the true discount on $Rs. 2500$ for the same time and at the same rate,the time is (in $years$)

After giving a discount of $20 \%$ on an article,a shopkeeper gains $20 \%$. What is the percentage mark-up?