The average age of $15$ students of a class is $15\, year.$ Oute of these, the average age of $5$ students is $14 \,year$ and that of the other $9$ students is $16\, year.$ The age of the $15^{th}$ students is? (in $year$)
$11$
$15$
$15 \frac{2}{7}$
$14$
The average of marks obtained by $120$ candidates in a certain examination is $35 .$ If the average marks obtained by passed candidates are $39$ and those of the failed candidates are $15,$ then what is the number of candidates who passed the examination?
There are $35$ students in a hostel. If the number of students increased by $7,$ the expenses of the mess were increased by $Rs.\,42$ per $day$ while the average expenditure per head decreased by $Rs.\,1$, Find out the actual expenditure of the mess. (in $Rs.$ )
The sum of three consecutive odd numbers is $38$ more than the average of these numbers. What is the first of these numbers
The average of the first $100$ positive integers is
A group of boys has an average weight of $36 \,kg$. One boy weighing $42 \,kg$ leaves the group and another boy weighing $30\, kg$ joints the group. If the average now becomes $35.7\, kg$, then how many boys are there in the group?