Quiz Discussion

The average age of the boys in a class is 16 years and that of the girls is 15 years. The average age for the whole class is-

• 1] 15 years
• 2] 15.5 years
• 3] 16 years
• 4] Cannot be computed with the given information

Of the three numbers, the first is twice the second and the second is twice the third. The average of the reciprocal of the numbers is 7/72. The numbers are:

• 1] 36, 18, 9
• 2] 24, 12, 6
• 3] 20, 10, 5
• 4] 16, 8, 4

Ten years ago, the ages of the members of a joint family of eight people added up to 231 years. Three years later, one member died at the age of 60 years and a child was born during the same year. After another three years, one more member died, again at 60, and a child was born during the same year. The current average of this eight-member joint family is nearest to-

• 1] 21 years
• 2] 22 years
• 3] 23 years
• 4] 24 years
• 5] 25 years

The average of x number is y and average of y numbers is x. Then the average of all the numbers taken together is

• 1]

  (x+y)/2xy

• 2]

  2xy/(x+y)

• 3]

  (x²+y²)/(x+y)

• 4]

  xy/(x+y)

The average age of husband, wife and their child 3 years ago was 27 years and that of wife and the child 5 years ago was 20 years. The present age of the husband is :

• 1] 40 years
• 2] 35 years
• 3] 50 years
• 4] None of the options