If $A$'s salary is $50 \%$ more than that of $B$,then $B$'s salary is less than $A$'s by

In an entrance examination,Ritu scored $56\%$ marks,Smita scored $92\%$ marks,and Rina scored $634$ marks. The maximum marks of the examination are $875$. What are the average marks scored by all the three girls together?

Two-thirds of three-fourths of one-fifth of a number is $15$. What is $30$ per cent of that number?

In an examination in which full marks were $800,$ $A$ gets $20 \%$ more than $B,$ $B$ gets $20 \%$ more than $C,$ and $C$ gets $15 \%$ less than $D.$ If $A$ got $576,$ what percentage of full marks did $D$ get (approximately) (in $\%$)?

In a mixture of milk and water,the proportion of water by weight was $75 \%$. If $15 \text{ gm}$ of water is added to $60 \text{ gm}$ of this mixture,what will be the new percentage of water by weight (in $\%$)?

Visions Pvt. Ltd. appoints a sales representative on a basic salary of $Rs. 1200$ per month, with the condition that for every $Rs. 10000$ of sales made above the initial $Rs. 10000$, he will receive $50\%$ of his basic salary and $10\%$ of that specific $Rs. 10000$ sales as a reward. There is no incentive for the first $Rs. 10000$ of sales. What should be the total value of sales if the sales representative wants to earn $Rs. 7600$ in a particular month?