If the selling price of $50$ articles is equal to the cost price of $40$ articles,then the loss or gain percent is:

Profit earned by an organization is distributed among officers and clerks in the ratio of $5:3$. If the number of officers is $45$ and the number of clerks is $80$ and the amount received by each officer is $Rs. 25,000$,what was the total amount of profit earned? (in $Rs.$ lakhs)

When a producer allows $36 \%$ concession on the retail price of his product,he earns a profit of $8.8 \% .$ What would be his profit percent if the concession is reduced by $24 \% ?$

$A$ shopkeeper sells notebooks at the rate of $Rs.\, 45$ each and earns a commission of $4 \%$. He also sells pencil boxes at the rate of $Rs.\, 80$ each and earns a commission of $20 \%$. How much total commission will he earn in two weeks if he sells $10$ notebooks and $6$ pencil boxes a day? (in $Rs.$)

$A$ sells a bicycle to $B$ at a profit of $20 \%.$ $B$ sells it to $C$ at a profit of $25 \%.$ If $C$ pays $Rs. 225$ for it,the cost price of the bicycle for $A$ is (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?