The average weight of a group of $20 \,boys$ was calculated to be $89.4\, kg$ and it was later discovered that one weight was misread as $78 \,kg$ instead of $87 \,kg.$ The correct average weight is (in $kg.$)
$88.95$
$89.25$
$89.55$
$89.85$
The average of three numbers is $135 .$ The largest number is $195$ and the diference between the other two is $20 .$ The smallest number is
The average weight of $A, B$ and $C$ is $84 \,kgs.$ If $D$ joins, the average weight now is $80 \,kgs$. If another person $E$ who is $3\, kgs$ heavier than $D$ replaces $A$ then the average weight of $B, C, D$ and $E$ becomes $79\, kgs.$ what is the weight of $A $ in $kg$ ?
If the difference between the average of $x, y$ and $y$, $z$ is $12,$ then the difference between $x$ and $z$ is
In a family, the average age of a father and a mother is $35\, years.$ The average age of the father, mother and their only son is $27\, years.$ What is the age of the son ? (in $years$)
A club has $15$ men and $25$ women. The average age of men is $10\, years$ and the average age of women is $12 \,year.$ What is the average age of the whole club in $year$?