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

Peter purchased a machine for $Rs. 80000$ and spent $Rs. 5000$ on repairs and $Rs. 1000$ on transport,then sold it with a $25\%$ profit. At what price did he sell the machine? (in $Rs$)

Aman buys $5$ laptops and $7$ computers for $Rs. 58500$. He sells the laptops at a profit of $10\%$ and computers at a profit of $16\%$ and his total gain is $Rs. 7110$. What price does he pay for a laptop? (in $Rs.$)

Paras Health Care made $3000$ strips of vitamin tablets at a cost of $Rs. 4800$. The company gave away $1000$ strips of tablets to doctors as free samples. $A$ discount of $25\%$ is given on the printed price. Find the ratio of profit in $Rs.$ if the price is raised from $Rs. 3.25$ to $Rs. 4.25$ per strip and if at the latter price,samples to doctors were done away with.

Meenal purchased a car for $Rs. 2,50,000$ and sold it for $Rs. 3,48,000$. What is the percent profit she made on the car?

$A$ shopkeeper allows a discount of $10 \%$ on the marked price of a camera. The marked price of the camera,which costs him $₹ 600$,to make a profit of $20 \%$ should be (in $₹$):