An article is sold at a profit of $20 \%$. If both the cost price and selling price are $Rs. 150$ less,the profit would be $5 \%$ more. Find the cost price.

Ram purchases a chair at $Rs. 70$ and spends $Rs. 17$ on its repair and $50$ paise on cartage. If he sells the chair at $Rs. 100$,then his approximate profit percentage will be?

An article is listed at $Rs. 65$. $A$ customer bought this article for $Rs. 56.16$ and received two successive discounts,of which one is $10 \%$. Find the other discount in this discount scheme offered by the shopkeeper (in $\%$).

$A$ man bought $15$ mangoes for a rupee. How many mangoes were sold for a rupee so that there is a loss of $25 \% ?$

$A$ trader marks the price of his goods $25 \%$ above the cost price but allows a $12.5 \%$ discount for cash payment. If he sells the goods for $Rs. 875$,find the cost price of the goods (in $Rs.$).

An article is sold for $Rs. 4950$ at a gain of $10 \%$. What would have been the gain or loss per cent if it had been sold for $Rs. 4275$?