There were $35$ students in a hostel. If the number of students increases by $7 ,$ the expenses of the mess increase by $Rs.\,42$ per $day$ while the average expenditure per head diminishes by $Rs.\,1$ Find the actual expenditure of the mess. (in $Rs.$)
$480$
$420$
$520$
$460$
A class has $20$ boys and $30$ girls. The average age of boys is $11\, years $ and that of girls is $12\,years.$ What is the average age of the whole class in $year$
The average of $25$ results is $20 .$ the average of first $12$ results is $15$ and that of the last $12$ results is $18 .$ Then, the $13^{ th}$ results is
The average marks obtained by $180$ students in an examination is $50 .$ If the average marks of passed students is $40 .$ Then what is the number of students who failed the examination ?
What was the average in $Rs.$ daily expenditure of a man in $1999$ who spent $Rs. \,6535$ in the first half year and $Rs.\, 88165$ in the last?
The average contribution of $5$ men to a fund is $Rs.\,35.$ A sixth man joins and pays $Rs.\,35$ more than the resultant average of $6$ men. The total contribution of all the six men is (in $Rs.$)