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):

$A$ $Rs. 750$ tin of cheese is offered at $8\%$ discount and a $Rs. 1,250$ tin of butter at $20\%$ discount. If we buy $5$ tins of cheese and $3$ tins of butter,what is the effective discount we get (in $\%$)?

$A$ trader marks the sale price $25\%$ more than the cost price and gives a $10\%$ discount at the time of selling. The gain percent is (in $\%$)

$A$ $20 \%$ discount is offered on an item. By applying a promo code,the customer wins $30 \%$ cash back. What is the effective discount? (in $\%$)

$A$ 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 $Rs.$)?

$A$ banker discounts a $4 \text{ months}$ bill at $3 \%$. If the proceeds are invested in a manner so that nothing is lost,the interest rate should be (in $\%$):