Quiz Discussion

A passenger travels from Delhi to Merut at a speed of 30 kmph and return with a speed of 60 kmph. What is the average speed?

• 1] 40
• 2] 45
• 3] 50
• 4] 48

If the mean of a,b,c is M and ab+bc+ca=0, then the mean of a²,b²,c² is:

• 1]

  M²

• 2]

  3M²

• 3]

  6M²

• 4]

  9M²

The average age of 40 students of class is 18 years. When 20 new students are admitted to the same class, the average age of the students of the class is increased by 6 months. The average age of newly admitted students is ?

• 1] 19 years
• 2] 19 years 6 months
• 3] 20 years
• 4] 20 years 6 months

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 salary of all the workers in a workshop is Rs.8000. The average salary of 7 technicians is Rs.12000 and the average salary of the rest is Rs.6000. The total number of workers in the workshop is

• 1]

  20

• 2]

  21

• 3]

  22

• 4]

  23

Out of four numbers the average of the first three is 16 and that of the last three is 15. If the last number is 20, than first number is :

• 1] 25
• 2] 21
• 3] 23
• 4] 28

The frequency distribution data is given below. If the average age is 17 years, the value of m is

• 1] 1
• 2] 2
• 3] 3
• 4] 4

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 average expenditure of a man for the first five months is Rs. 1200 and for the next seven months is Rs. 1300. If he saves Rs. 2900 in that year, his monthly average income is-

• 1] Rs. 1500
• 2] Rs. 1600
• 3] Rs. 1700
• 4] Rs. 1400

The average of six numbers is 3.95. The average of two of them is 3.4, while the average of the other two is 3.85. The average of the remaining two numbers is :

• 1] 4.6
• 2] 4.8
• 3] 4.5
• 4] 4.7