$A$ shopkeeper sells goods at $10 \%$ loss on cost price,but uses $20 \%$ less weight. What is his profit or loss percentage?

$A$ person earns $15 \%$ on an investment but loses $10 \%$ on another investment. If the ratio of the two investments is $3:5$,what is the gain or loss percentage on the two investments taken together (in $\%$)?

$A$ man bought oranges at the rate of $8$ for $Rs. 34$ and sold them at the rate of $12$ for $Rs. 57$. How many oranges should be sold to earn a net profit of $Rs. 45$?

$A$ machine is sold at a profit of $15 \%$. Had it been sold for $Rs\, 540$ more,$24 \%$ would have been gained. Find the cost price.

$A$ person sold a horse at a gain of $15 \%$. Had he bought it for $25 \%$ less and sold it for $₹ 60$ less,he would have made a profit of $32 \%$. The cost price of the horse was (in $₹$):

Nutan bought a watch with $24 \%$ discount. If she pays $Rs. 779$ for that watch,then what is the marked price of the watch in $Rs.$?