A batsman makes a score of $8$ runs in the $16^{\text {th }}$ match and thus increases his average runs per match by $3 .$ What is his average after the $16^{\text {th }}$ match?

The average of the first $100$ positive integers is

Out of four numbers the average of the first three is $16$ and that of the last three is $15 .$ If the last number is $20$ then the first number is

The arithmetie mean of the scores of a group of students in a test was $52 .$ The brightest $20 \%$ of them secured a mean score of $80$ and the dullest $25 \%$ a mean score of $31.$ The mean score of remaining $55 \%$ is

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

The average of $20$ numbers is $30$ and that of other $30$ numbers is $50 .$ What is the average of all the numbers.