The average of $50$ numbers is $38 .$ If two numbers, namely, $45$ and $55$ are discarded, what is the average of the remaining numbers ?
$37.5$
$38.5$
$39.5$
$36.5$
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?
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
The average salary of all workers in a workshop is $Rs.\, 12000 .$ The average salary of $7$ technicians is $Rs.\, 15000$ and the aterage salary of the rest in $Rs.\, 9000$. The total number of workers in the workshop is:
What is the average of first $7$ multiples of $7\, ?$
The average age of students of a class is $15.8 \,years.$ The average age of boys in the class is $16.4$ $years$ and that of the girls is $15.4\, years.$ The ratio of number of boys to the number of girls in the class is: