Quiz Discussion

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

In a school with 600 students, the average age of the boys is 12 years and that of the girls is 11 years. If the average of the school is 11 years 9 months, then the average the number of girls in the school is :

• 1] 150
• 2] 250
• 3] 350
• 4] 450

A man has 'n' magical eggs whose average weight is 'k' gm. Each of the 'n' eggs produces 'n' eggs next day such that the average weight of 'n' eggs produced is same as that of the parental egg for each 'n' groups individually i.e. each egg produces 'n' eggs of next generation and average weight of all the 'n' eggs of next generation is same as the weight of the mother egg. This process is continued without any change in pattern. What is the total weight of all the eggs of rth generation, where the initial number of eggs with man are considered as the eggs of first generation.

• 1] rnk
• 2] rnk
• 3] nkr
• 4] nrk
• 5] None of these

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

If 25a + 25b = 115, what is the average of a and b?

• 1] 2.5
• 2] 3.4
• 3] 4.5
• 4] 4.6
• 5] None of these

The average age of the mother and her six children is 12 years which is reduced by 5 years if the age of the mother is excluded. How old is the mother ?

• 1] 40 years
• 2] 42 years
• 3] 48 years
• 4] 50 years

There were 35 students in a hostel. Due to the admission of 7 new students the expenses of the mess were increased by Rs.42 per day while the average expenditure per head diminished by Re 1. What was the original expenditure of the mess?

• 1] Rs. 450
• 2] Rs. 320
• 3] Rs. 550
• 4] Rs. 420

3 years age, the average age of a family of 5 members was 17 years. A baby having been born, the average age of the family is same today. The present age of the baby is :

• 1]

  1 years

• 2]

  \(1\frac{1}{2} \)years

• 3]

  2 years

• 4]

  3 years

The average of 11 players of a cricket team is decreased by 2 months when two of them aged 17 years and 20 years are replaced by two new players. The average age of the new players is-

• 1] 17 years 1 month
• 2] 17 years 7 months
• 3] 17 years 11 months
• 4] 18 years 3 months

The mean of 100 observations was calculated as 40. It was founder later on that one of the observation was misread as 83 instead of 53. The correct mean is :

• 1] 39
• 2] 39.7
• 3] 40.3
• 4] 42.7