The average monthly salary of all the employees in an industry is $Rs. 12,000$. The average salary of male employees is $Rs. 15,000$ and that of female employees is $Rs. 8,000$. What is the ratio of male employees to female employees?

$A$ batsman,in his $12^{th}$ innings,makes a score of $63$ runs and thereby increases his average score by $2.$ The average of his score after $12^{th}$ innings is

The average speed of a cyclist who covers the first,second,and third km at $20, 16,$ and $12 \, km/hr$ respectively (in $km/hr$) is:

The average of $100$ observations was calculated as $35$. It was found later that one of the observations was misread as $83$ instead of $53$. The correct average is: (in $.7$)

There are two groups $A$ and $B$ of a class,consisting of $42$ and $28$ students,respectively. If the average weight of group $A$ is $25 \, kg$ and that of group $B$ is $40 \, kg$,find the average weight of the whole class.

$A$ professional institute's total expenditure on students for a particular course is partly fixed and partly varies linearly with the number of students. The average expense per student is $Rs.\,615$ when there are $24$ students and $Rs.\,465$ when there are $40$ students. What is the average expense when there are $60$ students? (in $Rs.$)