True discount on $Rs. 3024$ due $6$ months hence is $Rs. 144$. The rate percent is: (in $\%$)

When a discount of $25 \%$ is given on a cruise trip,the profit is $41 \% .$ If the discount is $26 \%,$ then the profit is (in $\%$)

$1$ 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?

The banker's gain on a certain sum of money due for $9$ months at $4 \%$ $p.a.$ is $Rs. 2.25$. The sum is (in $Rs.$)

If after giving a discount of $18 \%$,a book is sold for $Rs. 1599$,what will be the marked price (in $Rs.$) of the book?

$A$ has to pay $Rs. 220$ to $B$ after $1$ year. $B$ asks $A$ to pay $Rs. 110$ in cash and defers the payment of the remaining $Rs. 110$ for $2$ years. $A$ agrees to it. Counting the rate of interest at $10\%$ per annum in this new mode of payment,which of the following is true?