If the shopkeeper sells an item at $Rs. 960$ which is marked as $Rs. 1200$, what is the discount he is offering? (in $\%$)

$A$ trader allows a discount of $15 \%$ on a trolley bag having a list price of $Rs. 1360$ and earns a profit of $15.6 \%$. What is the cost price (in $Rs.$) of the trolley bag?

If the simple interest on a certain sum for some years at $6 \%$ is $Rs. 180$,and the true discount at $5 \%$ on the same amount for the same time is $Rs. 140$,find the sum (in $Rs.$) and the time (in $years$).

Successive discounts of $20 \%$ and $10 \%$ are given on an item marked at $Rs. 700$. Find the selling price (in $Rs.$).

If $21 \%$ of an electricity bill is discounted,$Rs. 1817$ is still to be paid. How much was the original bill amount? (in $Rs.$)

If $60 \%$ discount is offered on the marked price and selling price becomes equal to cost price,then what was the percentage mark up?