$A$ dealer sold two types of goods for $Rs. 10,000$ each. On one of them,he lost $20 \%$ and on the other he gained $20 \%$. His gain or loss per cent in the entire transaction was

The cost price of $100$ books is equal to the selling price of $60$ books. The gain or loss percentage will be:

$A$ 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 $\%$)

The marked price of an article is $Rs. 5000$. Due to a special festive offer,a certain percentage of discount is declared. Mr. $X$ availed this opportunity and bought the article at the reduced price. He then sold it at $Rs. 5000$ and thereby made a profit of $11 \frac{1}{9} \%$. The percentage of discount allowed was:

$A$ tradesman gives $4 \%$ discount on the marked price and gives one article free for buying every $15$ articles and thus gains $35 \%$. The marked price is approximately how much percent above the $CP$?

$A$ rice trader buys $8$ quintals of rice for $Rs. 3,600$. $10\%$ of the rice is lost in transportation. At what rate should he sell the remaining rice to earn a $15\%$ profit in $Rs.$ per quintal?