The average of 80 boys in a class is 15. The average age of a group of 15 boys in the class is 16 and the average age of…

In a primary school the average weight of male students is 65.9 kg and the average weight of female students is 57 kg. I…

The average age of group of 20 girls is 15 years and that of another group of 25 boys it is 24 years. The average age o…

A student finds the average of 10 positive integers. Each integer contains two digits. By mistake, the boy interchanges …

In an engineering college the average salary of all engineering graduates from Mechanical trade is Rs. 2.45 lacs per ann…

A family consists of grandparents, parents and three grandchildren. The average age of the grandparents is 67 years that…

The average weight of 15 students in a class increases by 1.5 kg when one of the students weighing 40 kg is replaced by …

The average salary, per head, of all the workers of an institution is Rs. 60. The average salary of 12 officers is Rs. 4…