$A$ 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 $\%$)

If the simple interest on a certain sum for some years at $6 \%$ is $Rs. 180$,and the true discount at $5 \%$ on the same amount for the same time is $Rs. 140$,find the sum (in $Rs.$) and the time (in $years$).

$A$ shopkeeper marks up his wares by $60 \%$ and offers a $10 \%$ discount. What will be the selling price (in $Rs.$) if the cost price is $Rs.\, 7500$?

$A$ dealer marks a washing machine for $Rs.\, 7500$ and allows a discount of $6 \%$ on it. Find its selling price in $Rs.$

$A$ bill which is due at the end of $4 \text{ years}$ is now worth $Rs. 575$,but if it is due in $2 \frac{1}{2} \text{ years}$,it would now be worth $Rs. 620$. The sum of the bill is (in $Rs.$)

$A$ shopkeeper gives two successive discounts of $7 \%$ each on the marked price of $Rs.\, 20,000$ of an article. The selling price of the article is (in $Rs.$):