$A$ manufacturer undertakes to supply $2000$ pieces of a particular component at $Rs. 25$ per piece. According to his estimates,even if $5\%$ fail to pass the quality tests,he will make a profit of $25\%$. However,as it turned out,$50\%$ of the components were rejected. What is the loss to the manufacturer? (in $Rs.$)

If a radio is purchased for $Rs. 490$ and sold for $Rs. 465.50$,find the $\text{loss} \%$. (in $\%$)

$A$ dealer sold a bicycle at a profit of $10 \%$. Had he bought the bicycle at $10 \%$ less price and sold it at a price $Rs. 60$ more,he would have gained $25 \%$. The cost price of the bicycle was:

$A$ businessman allows a discount of $10 \%$ on the marked price. What percent above the cost price must he mark his goods to make a profit of $17 \% ?$

If the cost price of $12$ pens is equal to the selling price of $8$ pens,find the gain percent.

$A$ fruit-seller buys some oranges and by selling $40 \%$ of them he realizes the cost price of all the oranges. As the oranges begin to grow over-ripe,he reduces the price and sells $80 \%$ of the remaining oranges at half the previous rate of profit. The rest of the oranges being rotten are thrown away. The overall percentage of profit is (in $\%$)