$A$ shopkeeper purchases two items for $Rs. 520$. One of them is sold at a gain of $16\%$ and the other at a loss of $10\%$,thus making no profit or loss. What is the selling price of the item sold at a loss?

$A$ man buys $100 \, kg$ of sugar for $Rs. \, 2400$. He sold $1/4$th of the stock at a loss of $5 \%$. At what per cent profit should he sell the remaining stock so as to make an overall profit of $20 \%$ on the whole transaction? (in $\%$)

$A$ person sold a radio at a loss of $5 \%$. Had he sold it for $Rs. 210$ more,he would have gained $25 \%$. For what value should he sell it in order to gain $35 \%?$

If cost price is $Rs. 150$ less than the selling price and profit is $20 \%$,then what is the selling price (in $Rs.$)?

Rahim bought a gift item for $Rs. 510$ after getting a discount of $15 \%$. He then sells it $5 \%$ above the marked price. The profit earned in this deal is (in $Rs.$)

$A$ trader purchases a wrist watch and a pendulum for $Rs. 390$. He sells them making a profit of $10 \%$ on the watch and $15 \%$ on the pendulum. He earns a total profit of $Rs. 51.50$. The difference between the original prices of the pendulum and the watch is equal to? (in $Rs.$)