$A$ watch dealer pays $10 \%$ customs duty on a watch which costs $Rs.\, 500$ abroad. He desires to make a profit of $20 \%$ after giving a discount of $25 \%$ to the buyer. The marked price should be (in $Rs.$)

$A$ $Rs. 750$ 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 $\%$)?

What rate of interest does a man get for his money when in discounting a bill due in $10 \, \text{months}$, he deducts $4 \%$ of the amount of the bill? (in $\%$)

After giving a discount of $20 \%$ on an article,a shopkeeper gains $20 \%$. What is the percentage mark-up?

$A$ cloth merchant has announced a $25 \%$ rebate in prices. If one needs to have a rebate of $Rs. 40$,then how many metres of cloth costing $Rs. 32$ per metre should he purchase?

$A$ 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?