When a discount of $Rs. 42$ is allowed on the marked price of an article,the new reduced price becomes $86 \%$ of the original marked price. Find the marked price (in $Rs.$).

$A$ owes $B$ $Rs. 1350$ due in $3$ months and $B$ owes $A$ $Rs. 1078$ due in $5$ months. If they agree to settle their account right now at $5\%$ $p.a.$ simple interest,how much should $A$ pay to $B$ (in $Rs.$)?

While selling a watch,a shopkeeper gives a discount of $5 \%$. If he gives a discount of $7 \%$,he earns $Rs. 15$ less as profit. The marked price of the watch is (in $Rs.$):

$1$ packet of biscuits costs $Rs.\, 16$,but a pack of $4$ of the same packets of biscuits costs $Rs.\, 56$. What is the effective discount (in $\%$) on the pack?

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 $Rs.$)

$A$ merchant marks an article $20\%$ above cost price. He then sells it at a discount of $20\%$. The sale gives him