$A$ man sold his two horses for $Rs. 770$ each. On one he gained $10\%$ and on the other he lost $10\%$. The average gain or loss percentage is:

$A$ shopkeeper mixes $20 \, kg$ of rice which cost him $Rs. \, 5$ per $kg$ with $35 \, kg$ of rice which cost him $Rs. \, 7$ per $kg$. Then he sells the mixture at $Rs. \, 6.5$ per $kg$. Find his total profit and percent profit.

If a stall sells a pizza at $Rs. 200$,he makes a $20 \%$ loss. If he wants to make a $10 \%$ profit,then at what price (in $Rs.$) should he sell it?

$A$ sells an article to $B$ at a gain of $20 \%$,$B$ sells it to $C$ at a gain of $10 \%$,and $C$ sells it to $D$ at a gain of $12 \frac{1}{2} \%$. If $D$ pays $Rs. 29.70$,what was the cost price for $A$? (in $Rs.$)

Kritika bought $25$ $i-pads$ and $i-phones$ for $Rs. 205000$. She sold $80\%$ of the $i-pads$ and $12$ $i-phones$ for a profit of $Rs. 40000$. Each $i-pad$ was marked up by $20\%$ over cost and each $i-phone$ was sold at a profit of $Rs. 2000$. The remaining $i-pads$ and $3$ $i-phones$ could not be sold. What is Kritika's overall profit/loss?

The cost price of $100$ books is equal to the selling price of $60$ books. The gain or loss percentage will be: