Quiz Discussion

The average weight of 47 balls is 4 g. if the weight of the bag (in which the balls are kept) be included; the calculated average weight per ball increases by 0.3 g. What is the weight of the bag?

• 1] 14.8 g
• 2] 14.4 g
• 3] 15 g
• 4] 18.6 g
• 5] None of these

The average of X1, X2 and X3 is 14. Twice the sum of X2 and X3 is 30. What is the value of X1?

• 1] 12
• 2] 16
• 3] 20
• 4] 27

The average of marks in Mathematics for 5 students was found to do 50. Later, it was discovered that in the case of one student the marks 48 were misread as 84. The correct average is :

• 1] 40.2
• 2] 40.8
• 3] 42.8
• 4] 48.2

If the average of x and 1/x(X\( \ne \)0) is M, then the average of x2 and 1/x² is :

• 1] 1 - M2
• 2] 1 - 2M2
• 3] 2M2 - 1
• 4] 2M2 + 1

The average of 10 items was found to be 80 but while calculating, one of the items was counted as 60 instead of 50. Then the correct average would have been :

• 1] 69
• 2] 79.25
• 3] 79
• 4] 79.5

10 years ago, the average age of a family of 4 members was 24 years. Two children having been born (with age difference of 2 years), the present average age of the family is again 24 years. Then the present age of the youngest child is:

• 1]

  1 years

• 2]

  2 years

• 3]

  3 years

• 4]

  4 years

The average of 9 observations was found to be 35. Later on, it was detected that an observation 81 was misread as 18. The correct average of the observation is -

• 1] 28
• 2] 42
• 3] 32
• 4] 45

Find the average of 1.11, 0.01, 0.101, 0.001, 0.11 = ?

• 1] 0.2664
• 2] 0.2554
• 3] 0.1264
• 4] 0.1165

The speed of the train going from Nagpur to Allahabad is 100 km/h while when coming back from Allahabad to Nagpur, its speed is 150 km/h. find the average speed during whole journey.

• 1] 125 km/hr
• 2] 75 km/hr
• 3] 135 km/hr
• 4] 120 km/hr

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