If the $CP$ of $50$ items is equal to the $SP$ of $40$ items,then what is the profit or loss $\%$ (in $\%$)?

If an item is sold for $Rs. 924$,there is a profit of $10\%$. What is the cost price?

The labelled price of a cupboard is $Rs. 6500$. The shopkeeper sold it by giving $5\%$ discount on the labelled price and earned a profit of $15\%$. What approximately is the cost price of the cupboard? (in $Rs.$)

If a man reduces the selling price of a fan from $Rs. 400$ to $Rs. 380$,his loss increases by $2 \%$. The cost price of the fan is (in $Rs.$)

At a cost of $60$ paise per article,Sarika produces $750$ articles. She sets the selling price such that if only $600$ articles are sold,she would have made a profit of $40 \%$ on the total outlay. However,$120$ articles got spoilt and she was able to sell $630$ articles at this price. Find her actual profit or loss percent as a percentage of the total outlay,assuming that the unsold articles are useless.

Two toys are sold at $Rs. 504$ each. One toy brings the dealer a gain of $12 \%$ and the other a loss of $4 \%$. The gain or loss percent by selling both the toys is