Quiz Discussion

From a class of 42 boys, a boy aged 10 years goes away and in his place, a new boy is admitted. If on account of this change, the average age of the boys in that class increases by 2 months, the age of the newcomer is :

• 1] 19 years
• 2] 17 years
• 3] 10 years 6 months
• 4] 12 years 2 months

The average of 6 numbers is 7. The average of three numbers of them is 5. What will be the average of remaining numbers?

• 1] 15
• 2] 30
• 3] 9
• 4] 42

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 monthly salary of 660 workers in a factory is Rs. 380. The average monthly salary of officers is Rs. 2100 and the average monthly salary of the other workers is Rs. 340. Find the number of other workers.

• 1] 645
• 2] 650
• 3] 640
• 4] 642

The average of five numbers is 7. If three new numbers would be added, then the new average comes out to be 8.5. What is the average of those three new numbers ?

• 1] 9
• 2] 10.5
• 3] 11
• 4] 11.5

The average weight of a group of 75 girls was calculated as 47 kgs. It was later discovered that the weight of one of the girls was read as 45 kgs. Whereas her actual weight was 25 kgs. What is the actual average weight of the group of 75 girls? ( Rounded off to two digits after decimal).

• 1] 34
• 2] 36
• 3] 30
• 4] None of these

The average of 50 numbers is 30. If two numbers, 35 and 40 are discarded, then the average of the remaining numbers is nearly:

• 1] 28.32
• 2] 29.68
• 3] 28.78
• 4] 29.27

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

The average score of a cricketer for ten matches is 38.9 runs. If the average for the first six matches is 42, then find the average for the last four matches.

• 1] 33.25
• 2] 33.5
• 3] 34.25
• 4] 35

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