A batsman has an average of $30$ runs in his $42$ inning. The difference between his maximum and minimum score is $100 .$ If these two innings are removed his average for $40$ innings comes down to $28 .$ What is his minimum score?

Average weight of $25$ persons is increased by $1 \,kg ,$ when one man weighing $60\, kg$ is replaced by a new person. Weight of new person is? (in $kg$)

The average of $50$ numbers is $30.$ If two numbers, $35$ and $40$ are discarded, then the average of the remaining numbers is nearly.

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

A group of boys has an average weight of $36 \,kg$. One boy weighing $42 \,kg$ leaves the group and another boy weighing $30\, kg$ joints the group. If the average now becomes $35.7\, kg$, then how many boys are there in the group?

In an examination the average marks was found to be $60.$ The marks of $80$ candidates had to be changed from $95$ to $70$ each and the average came down to $55$ marks. The total number of candidates attended the examination were