Quiz Discussion

The average of 6 observations is 45.5. If one new observation is added to the previous observations, then the new average becomes 47. The new observation is :

• 1] 58
• 2] 56
• 3] 50
• 4] 46

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

The mean of 100 items was 46. Later on it was discovered that an item 16 was misread as 61 and another item 43 was misread as 34. It was also found that the number of item was 90 and not 100. Then what is the correct mean ?

• 1] 50
• 2] 50.7
• 3] 52
• 4] 52.7

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

• 1] 12
• 2] 18
• 3] 14
• 4] 16

Average of 80 numbers are 42. When 5 more numbers are included, the average of 85 numbers become 45. Find the average of 5 numbers.

• 1] 82
• 2] 89
• 3] 93
• 4] 98

The average price of 10 books is Rs.12 while the average price of 8 of these books is Rs.11.75. Of the remaining two books, if the price of one book is 60% more than the price of the other, what is the price of each of these two books?

• 1] Rs. 5, Rs.7.50
• 2] Rs. 8, Rs. 12
• 3] Rs. 16, Rs. 10
• 4] Rs. 12, Rs. 14

There are two sections A and B of a class, consisting of 36 and 44 students' respectively. If the average weight of section A is 40kg and that of section B is 35kg, find the average weight of the whole class.

• 1] 30 kg
• 2] 35 kg
• 3] 42.5 kg
• 4] 37.25 kg

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)

A cricketer scored some runs in his 21st innings, as a result, his average runs increased by 3. If the present average run is 40, how many runs he scored in the final innings?

• 1] 103
• 2] 100
• 3] 85
• 4] 82

The average weight of 8 men is increased by 1.5 kg when one of the men, who weight 65 kg is replaced by a new man. The weight of the new man is-

• 1] 70 kg
• 2] 74 kg
• 3] 76 kg
• 4] 77 kg