Quiz Discussion

40% of the employees in a factory are workers. All the remaining employees are executives. The annual income of each worker is Rs. 390. The annual income of each executive is Rs. 420. What is the average annual income of all the employees in the factory together?

• 1] 390
• 2] 405
• 3] 408
• 4] 415

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 of the two groups mixed together is :

• 1] 19.5 yearas
• 2] 20 years
• 3] 21 yearas
• 4] 21.5 years

The average age of a family of 10 members is 20 years. If the age of the youngest member of the family is 10 years, then the average age of the members of the family just before the birth of the youngest member was approximately.

• 1]

  27.14 years

• 2]

  12.5 years

• 3]

  14.28 years

• 4]

  \(11\frac{1}{9}\) years

In a set of three numbers, the average of first two numbers is 2, the average of the last two numbers is 3, and the average of the first and the last numbers is 4. What is the average of three numbers?

• 1] 2
• 2] 2.5
• 3] 3
• 4] 3.5

The average age of students of a class is 15.8 years. The average age of boys in the class is 16.4 years and that of the girls is 15.4 years. The ratio of the number of boys to the number of girls in the class is-

• 1] 1 : 2
• 2] 2 : 3
• 3] 3 : 4
• 4] 3 : 5

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

• 1] x = y + z
• 2] 2x = y + z
• 3] x = 2y + 2z
• 4] None of these

The present age of a father is 3 years more than three times the age of his son. Three years hence, father's age will be 10 years more than twice the age of the son. The father's age is :

• 1] 33 years
• 2] 39 years
• 3] 45 years
• 4] 40 years

The average weight of 10 oarsmen in a boat is increased by 1.5kg when one of the crew who weighs 58kg is replaced by a new man.

• 1]

  73 Kg

• 2]

  64 Kg

• 3]

  12 Kg

• 4]

  34 Kg

The average age of 30 students of a class is 14 years 4 months. After admission of 5 new students in the class the average becomes 13 years 9 months. The youngest one of the five new students is 9 years 11 months old. The average age of the remaining 4 new students is :

• 1] 10 years 4 months
• 2] 12 years 4 months
• 3] 11 years 2 months
• 4] 13 years 6 months

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)