Quiz Discussion

The average of six numbers is x and the average of three of these is y. If the average of the remaining three is z, then-

• 1] x = y + z
• 2] 2x = y + z
• 3] x = 2y + 2z
• 4] None of these

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

Out of 20 boys, 6 are each of 1 m 15 cm height, 8 are of 1 m 10 cm and rest of 1 m 12 cm. The average height of all of them is :

• 1] 1 m 12.1 cm
• 2] 1 m 21.1 cm
• 3] 1 m 21 cm
• 4] 1 m 12 cm

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

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

Sachin Tendulkar has a certain average for 11 innings. In the 12th innings he scores 120 runs and thereby increases his average by 5 runs. His new average is :

• 1] 60
• 2] 62
• 3] 65
• 4] 66

In the first 10 overs of a cricket game, the run rate was only 3.2. The run rate in the remaining 40 overs to reach the target of 282 run is :

• 1] 6.4
• 2] 6.3
• 3] 6.25
• 4] 6.5

Four years ago, the average age of A and B was 18 years. At present the average age of A, B, and C is 24 years. What would be the age of C after 8 years?

• 1] 25 years
• 2] 28 years
• 3] 32 years
• 4] 36 years

The average of the first 100 positive integers is-

• 1] 49.5
• 2] 50.5
• 3] 51
• 4] 100

The average of the first five multiples of 3 is-

• 1] 3
• 2] 9
• 3] 12
• 4] 15