$A$ fair price shopkeeper takes $10 \%$ profit on his goods. He lost $20 \%$ of his goods due to theft. What is his loss percentage (in $\%$)?

$A$ person purchases $8$ pens for ₹ $10$ and sells $10$ pens for ₹ $8$. How much profit or loss percentage does he make?

Sarita sells a phone at a profit of $20 \%$. If she had bought it at $20 \%$ less and sold it for $Rs. 180$ less, she would have gained $25 \%$. Find the cost price of the phone in $Rs.$

$A$ shopkeeper labeled the price of his articles in order to earn a profit of $30 \%$ on the cost price. He,then,sold the articles by offering a discount of $10 \%$ on the labelled price. What is the actual rate of profit he earned in the deal? (in $\%$)

Aditya purchased $14$ shirts and $25$ pants at $Rs. 45$ and $Rs. 55$ respectively. What should be the approximate overall average selling price of a shirt and a pant so that a $40\%$ profit is earned?

Profit obtained on selling an article for $Rs. 310$ is equal to the loss incurred on selling that article for $Rs. 230$. What will be the loss percentage when selling price is $Rs. 180$?