By selling $80$ ball pens for $₹ 140$,a retailer loses $30 \%$. How many ball pens should he sell for $₹ 104$ so as to make a profit of $30 \% ?$

Rehaan purchased a bike for $Rs. 54,000$. He sold it at a loss of $8\%$. With that money, he again purchased another bike and sold that at a profit of $10\%$. What is his overall loss or profit?

$A$ man buys $10$ articles for $Rs. 8$ and sells them at $Rs. 1.25$ per article. His gain percent is

Harkesh bought a certain quantity of tomato at the rate of $Rs. 1500$ per quintal. $10 \%$ of the tomato was spoiled. At what price in $Rs.$ per quintal should he sell the remaining to gain $20 \%$ of his outlay?

$A$ 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:

$A$ manufacturer fixes his selling price at $33 \%$ over the cost of production. If the cost of production goes up by $12 \%$ and the manufacturer raises his selling price by $10 \%$,what is his new percentage profit?