An $Ox$ and a carriage together cost $Rs.$ $8000$ The ox is sold at profit of $10 \%$ and carriage is sold at loss of $10 \% .$ If total profit made is $2.5 \%$ then what is the cost price of the $ox$? (in $Rs.$)

If a vendor sells a coconut at $Rs.\, 14.4$ he makes $10 \%$ Ioss. If he wants to make $25 \%$ profit, there at what price (in $Rs.$) should he sell?

A pen was sold for a certain sum and there was a loss of $20 \% .$ Had it been sold for $Rs.\, 12$ more, there would have been a gain of $30 \% .$ What would be the profit if the pen was sold for $Rs.\, 4.80$ more than what it was sold for? (in $\%$)

A man loses $20 \frac{1}{2} \%$ of his money and after spending $80 \%$ of the remainder, he is left with $Rs.\, 159 .$ How much did he have at first? (in $Rs.$)

A person sells $36$ apple per rupee and suffers a loss of $4 \% .$ Find how many apple per rupees to be sold to have a gain of $8 \%$.

Arun marks up the computer he is selling by $20 \%$ profit and sells them at a discount of $15 \%$. Arun's net gain percent is