Last year, $5$ companies had an average of $16$ non working days each, and $2$ companies had $5$ fewer non working days each. What was the average number of non working days given by the same companies this $year$ ?

The average weight of $45$ students in a class is $52\, kg.$ Five of them whose average weight is $48 \,kg$ leave the class and other $5\, students$ whose average weight is $54\, kg$ join the class. What is the new average weight (in $kg$ ) of the class 

The average pocket-money of $3$ friends $A, B, C$ is $Rs.\, 80$ $month.$ If $B$ spends double and $C$ spends triple of whate $A$ spends during that month and if the average of their unspent pocketemoney is $Rs.$ $60,$ then $A$ spends (in $Rs.$)

In an examination, out of $20$ students in a class, in Mathematics $2$ students scored $100$ marks $, 3$ students scored $0,$ and average marks for rest of the students was $40 .$ What is the average mark of the whole class ? (in $marks$)

Find the average of first $25$ multiples of $5 .$

Of three numbers, the second is thrice the first and the third number is three-fourths of the first.If the average of the three numbers is $114,$ the largest number is