$A$ man sold two cows at $Rs. 1995$ each. On one he lost $10\%$ and on the other he gained $10\%$. What is his gain or loss percent (in $\%$)?

$A$ tradesman gives $4 \%$ discount on the marked price and gives one article free for buying every $15$ articles and thus gains $35 \%$. The marked price is approximately how much percent above the $CP$?

The ratio between the selling price and the cost price of an article is $7:5$. What is the ratio between the profit and the cost price of that article?

$A$ shopkeeper sells a badminton racket,whose marked price is $Rs. 30$,at a discount of $15\%$ and gives a shuttlecock costing $Rs. 1.50$ free with each racket. Even then,he makes a profit of $20\%$. His cost price per racket is (in $Rs$):

$A$ person sells a colour $TV$ at $10\%$ below the cost price. Had he received $Rs. 1494$ more,he would have made a profit of $12 \frac{1}{2}\%$. What was the cost price of the colour $TV$ (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 $Rs.$)