$16$ children are to be divided into two groups $A$ and $B$ of $10$ and $6$ children. The average percent marks obtained by the children of group $A$ is $75$ and the average per cent marks of all the $16$ children is $76 .$ What is the average per cent marks of children of group $B$ ?

The average of the two-digit numbers, which remain the same when the digits interchange their position is

The average marks of a class of $35$ children is $35 .$ The marks of one of the students, who got $35,$ was incorrectly entered as $65 .$ What is the correct average of the class?

The average salary of all the associates in a team is $Rs.\,16000.$ The average salary of $7$ senior associates is $Rs.\,24000$ and the average salary of the rest is $Rs.\, 12000$. How many associates work in that team?

The average of $13$ results is $50 .$ If the average of first $7$ results is $52$ and that of last $7$ results is $49,$ find the $7^{th}$ result.