The average weight of $100$ students is $32\, kg$. The average weight of first $49$ students is $30\, kg$ and that of last $50$ students is $34\, kg$. What is the weight (in $kg$ ) of the $50^{ th }$ student ?

A batsman in his $17^{th}$ innings, makes a score of $85$ runs, and there by, increases his average by $3$ runs. What is his average after the $17^{th}$ innings ? He had never been $'not out'.$

The average marks of a student obtained in Physics, Chemistry and Biology is $70.$ If the student obtained $90\, marks$ in Mathematics, then the new average is

The average marks of $40$ students in an English exam is $72 .$ Later it is found that three marks $64 , 62$ and $84$ were wrongly entered as $68,65$ and $73.$ The average after mistakes were rectified is

What is the age of a class teacher?

$I.$ There are $11$ students in the class.

$II.$ The average age of the students and the teacher is $14$ years.

$III.$ The average age of the teacher and the students is $3$ years more than that of the students.

Roshan bought $5$ pants at $Rs.\, 25$ each, $10$ shirts at $Rs.\, 50$ each and $15$ ties at $Rs.\, 35$ each. Find the average price of all the articles in $Rs.$