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 $year.$

The mean daily profit made by a shopkeeper, in a month of $30\, days,$ was $Rs.\,350.$ If the mean profit for the first $15\, days$ was $Rs.\, 275,$ then the mean profit for the last $15\, days$ would be (in $Rs\,$)

Of the three numbers, the second is twice the first and thrice the third. If the average of the three numbers is $44,$ then the largest number is

Mr. Patel walked $6\,km$ to reach the station from his house, then he boarded a train whose average speed was $60 \,km / hr$ and thus he reached his destination. In this way he took total of $3\, hours.$ If the average speed of the entire journey was $32\, km / hr$ then the average speed of walking is (in $km/hr$)

The average weight of five persons sitting in a boat is $38\, kg.$ The average weight of the boat and the persons sitting in the boat is $52\, kg.$ What is the weight of the boat (in $kg$)?

If the mean of $5$ observation $x, x+2, x+4, x+6$ and $x+8$ is $11,$ then the mean of the last three observations is