Quiz Discussion

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)

Five years ago the average age of A, B, C, D was 45 years. By including X the present average of all the five is 49 years. Them the present age of X is-

• 1] 40 years
• 2] 45 years
• 3] 48 years
• 4] 64 years

A man travels equal distances of his journey at 40, 30 and 15 km/h. respectively. Find his average speed for whole journey.

• 1] 24
• 2] 25
• 3] 27
• 4] 28

Find the average of the first 40 natural numbers.

• 1]

  21

• 2]

  20.5

• 3]

  21.5

• 4]

  None Of These

The average of six number is x and the average of three of these is y. the average of the remaining three is z, then 

• 1]

  x=y+z

• 2]

  2x=y+z

• 3]

  x=2y+2z

• 4]

  x=2yz

Find the average increase rate, if increase in the population in the first year is 30% and that in the second year is 40%.

• 1] 41%
• 2] 56%
• 3] 40%
• 4] 38%
• 5] 39%

In a school with 600 students, the average age of the boys is 12 years and that of the girls is 11 years. If the average of the school is 11 years 9 months, then the average the number of girls in the school is :

• 1] 150
• 2] 250
• 3] 350
• 4] 450

Four years ago, the average age of A and B was 18 years. At present the average age of A, B, and C is 24 years. What would be the age of C after 8 years?

• 1] 25 years
• 2] 28 years
• 3] 32 years
• 4] 36 years

The average of four consecutive even numbers is 15. The 2nd highest number is :

• 1] 12
• 2] 18
• 3] 14
• 4] 16

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