$A$ person sells two articles,each for $Rs. 1040$. He incurs a $20\%$ loss on the first and a $10\%$ loss on the second. Find the overall percentage loss. (in $\%$)

$A$ sells an article to $B$ at a profit of $20 \%$ and $B$ sells it to $C$ at a loss of $10 \%$. If $C$ pays $Rs. 540$ for it,at what price did $A$ buy?

If the cost price of $20$ articles is equal to the selling price of $15$ articles,find the profit percent?

$A$ cab driver makes a profit of $20 \%$ on every trip when he carries $3$ passengers and the price of petrol is $Rs. 30$ a litre. Find the percentage profit for the same journey if he goes with four passengers per trip and the price of petrol reduces to $Rs. 24$ a litre? (in $\%$)
(Assume that revenue per passenger is the same in both the cases.)

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 $30 \%$?

$A$ shopkeeper allows $23 \%$ commission on his advertised price and still makes a profit of $10 \%$. If he gains $₹ 56$ on one item,what is the advertised price of the item in $₹$?