Quiz Discussion

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 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 sale of car dealership was 15 cars per week. After a promotional scheme the average sale increased to 21 cars per week. The percentage increased in the sale of cars was-

• 1]

  39.33%

• 2]

  40%

• 3]

  \(42\frac{6}{7}\)%

• 4]

  140%

The average age of 3 children in a family is 20% of the average age of the father and the eldest child. The total age of the mother and the youngest child is 39 years. If the father's age is 26 years, what is the age of the second child ?

• 1] 15 years
• 2] 18 years
• 3] 20 years
• 4] Cannot be determined

A cricketer whose bowling average is 12.4 runs per wicket takes 5 wickets for 26 runs and thereby decreased his average by 0.4. The number of wickets taken by him the last match was-

• 1] 64
• 2] 72
• 3] 80
• 4] 85

30 pens and 75 pencils altogether were purchased for Rs. 510. If the average price of a pencil was Rs. 2, what was the average price of a pen ?

• 1] Rs. 9
• 2] Rs. 10
• 3] Rs. 11
• 4] Rs. 12

The average weight of 47 balls is 4 g. if the weight of the bag (in which the balls are kept) be included; the calculated average weight per ball increases by 0.3 g. What is the weight of the bag?

• 1] 14.8 g
• 2] 14.4 g
• 3] 15 g
• 4] 18.6 g
• 5] None of these

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

The mean high temperature of the first four days of a week is 25°C whereas the mean of the last four days is 25.5°C. If the mean of the whole week is 25.2°C then the temperature of the 4th day is :

• 1] 25°C
• 2] 25.2°C
• 3] 25.6°C
• 4] 25.5°C

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