The average age of mother, father and son was $42\, years.$ at the time of the marriage of the son. After one year an infant was born in the family and after $6\, years$ of marriage the average age of the family is $36\, years.$ What was the age of the bride at the time of marriage in $year.$
$25$
$23$
$22$
$24$
The average of certain first consecutive natural numbers is $20.5 .$ Find their sum.
The average salary per head of all the workers in a workshop is $Rs.\,850.$ If the average salary per head of $7$ technicians is $Rs.\, 1000$ and the average salary per head of the rest is $Rs.\, 780,$ find out the total number of workers in the workshop.
The average monthly expenditure of a family for the first four months is $Rs.\, 2570$, for the next three months $Rs.\, 2490$ and for the last five months $Rs.\,3030.$ If the family saves $Rs.\, 5320$ during the whole $year,$ the average monthly income of the family during the year is (in $Rs.\,$)
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
Of the three numbers whose average is $60,$ the first is one-fourth of the sum of the others. The first number is