$A$ man buys $10$ oranges for a rupee and sells $8$ oranges for a rupee. What is the profit percent?

$A$ dairyman pays $Rs. 6.40$ per litre of milk. He adds water and sells the mixture at $Rs. 8$ per litre,thereby making $37.5\%$ profit. The proportion of water to milk received by the customers is

$A$ fruit-seller buys $x$ guavas for $Rs. y$ and sells $y$ guavas for $Rs. x$. If $x > y$,then he made:

$A$ manufacturer sells an article to a wholesale dealer at a profit of $10 \%$. The wholesale dealer sells it to a shopkeeper at $20 \%$ profit. The shopkeeper sells it to a customer for $₹ 56,100$ at a loss of $15 \%$. Then the cost price of the article to the manufacturer is (in $₹$) (in $,000$)

$A$ shopkeeper wishes to give $5 \%$ commission on the marked price of an article but also wants to earn a profit of $10 \%$. If his cost price is $₹ 95$,then the marked price is (in $₹$):

Find a simple discount equivalent to a discount series of $10 \%, 20 \%$ and $25 \%$ (in $\%$).