What will be the net discount (in $percentage$) after two successive discounts of $50 \%$ and $50 \% ?$

Ticket for an adult is $Rs. 1500$ and that of a child is $Rs. 800$. One child goes free with two adults. If a group has $25$ adults and $12$ children,what is the discount the group gets? (in $\%$)

The present worth of $Rs. 220.50$ due in $2$ years reckoning compound interest at $5 \%$ per annum is (in $Rs.$):

If two successive discounts of $20 \%$ and $30 \%$ are given,what is the net discount (in $\%$) ?

The true discount on a bill due $10$ months hence at $15 \%$ per annum is $Rs. 225$. The amount of the bill is (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 $Rs.$)