The average of $5$ quantities is $6 .$ The average of three of them is $8 .$ What is the average of remaining two quantities?

Of the three numbers, second is twice the first and is also thrice the third. If the average of the three numbers is $44,$ the largest number is

The average of first three numbers is double of the fourth number. If the average of all the four numbers is $12,$ find the $4^{th}$ number.

The average weight of $3$ men $A, B$ and $C$ is $84 \,k g .$ Another man, $D,$ joins the group, and the average weight becomes $80\, kg .$ If another man, $E$, whose weight is $3 \,kg$ more than that of $D ,$ replaces $A$, then average weight of $B , C , D$ and $E$ becomes $79 \,kg$. The weight of $A$ is (in $kg$)

The average of $30$ numbers is $15 .$ The average of the first $18$ numbers is $10$ and that of the next $11$ numbers is $20 .$ The last number is

The average age of four brothers is $12 \,year.$ If the age of their mother be also included, the average is increased by $5\, year.$ The age of the mother (in $years$) is