Quiz Discussion

The average age of 30 students of a class is 14 years 4 months. After admission of 5 new students in the class the average becomes 13 years 9 months. The youngest one of the five new students is 9 years 11 months old. The average age of the remaining 4 new students is :

• 1] 10 years 4 months
• 2] 12 years 4 months
• 3] 11 years 2 months
• 4] 13 years 6 months

A librarian purchased 50 storybooks for his library. But he saw that he could get 14 books more by spending Rs. 76 more but per book average becomes Rs. 1 less. The average price (in Rs.) of each book he bought, was :

• 1] 15
• 2] 25
• 3] 20
• 4] 10

The average age of three boys is 15 years. If their ages are in ratio 3 : 5 : 7, the age of the youngest boy is

• 1] 21 years
• 2] 18 years
• 3] 15 years
• 4] 9 years
• 5] 12 years

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

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

The average age of students of a class is 15.8 years. The average age of boys in the class is 16.4 years and that of the girls is 15.4 years. The ratio of the number of boys to the number of girls in the class is-

• 1] 1 : 2
• 2] 2 : 3
• 3] 3 : 4
• 4] 3 : 5

A cricketer had a certain average of runs for his 64 innings. In his 65th innings, he is bowled out for no score on his part. This brings down his average by 2 runs. His new average of runs is :

• 1] 130
• 2] 128
• 3] 70
• 4] 68

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

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 score of a class of boys and girls in an examination is A. The ratio of boys and girls in the class is 3 : 1. If the average score of the boys is A + 1, the average score of the girls is-

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