If the cost price of $20$ tables is equal to the selling price of $25$ tables,find the loss percentage. (in $\%$)

$A$ shopkeeper allows a discount of $10\%$ on the marked price of an item but charges a sales tax of $8\%$ on the discounted price. If the customer pays $Rs. 3,402$ as the price including the sales tax,then the marked price is (in $Rs.$)

$A$ sells a good to $B$ at a profit of $10 \%$ and $B$ sells it to $C$ at a profit of $20 \%$. Find out the resultant profit percentage.

$A$ dishonest dealer defrauds to the extent of $x \%$ in buying as well as selling his goods by using faulty weight. What will be the gain per cent on his outlay?

$A$ dishonest dealer professes to sell his goods at cost price but uses a weight of $960 \, g$ instead of a $1 \, kg$ weight. Find his gain $\%$. (in $\%$)

$A$ 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 $\%$)