Quiz Discussion

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

Nine persons went to a hotel for taking their meals. Eight of them spent Rs. 12 each on their meals and the ninth spent Rs. 8 more than the average expenditure of all the nine. What was the total money spent by them.

• 1] Rs. 115
• 2] Rs. 116
• 3] Rs. 117
• 4] Rs. 118

Mean of 10 numbers is 30. Later on it was observed that numbers 15, 23 are wrongly taken as 51, 32. The correct mean is :

• 1] 25.5
• 2] 32
• 3] 30
• 4] 34.5

In a family, the average age of a father and a mother is 35 years. The average age of the father, mother and their only son is 27 years. What is the age of the son?

• 1] 10 years
• 2] 10.5 years
• 3] 11 years
• 4] 12 years

The average age of A, B, C, D and E is 40 years. The average age of A and B is 35 years and the average of C and D is 42 years. Age of E is :

• 1] 48 years
• 2] 46 years
• 3] 42 years
• 4] 45 years

The average (arithmetic mean) of 330, 360 and 390 is :

• 1]

  \({3^{27}} + {3^{57}} + {3^{87}}\)

• 2]

  \({3^{29}} + {3^{59}} + {3^{89}}\)

• 3]

  \({3^{60}}\)

• 4]

  \({3^{177}}\)

The average marks obtained by a class of 60 students is 65. The average marks of half of the students is found to be 85. The average marks of the remaining students is :

• 1] 35
• 2] 45
• 3] 55
• 4] 65

A school has only four classes that contain 10, 20, 30 and 40 students respectively. The pass percentage of these classes are 20%, 30%, 60% and 100% respectively. Find the pass % of the entire school.

• 1] 56%
• 2] 76%
• 3] 34%
• 4] 66%
• 5] None of these

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

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