Quiz Discussion

In a set of three numbers, the average of first two numbers is 2, the average of the last two numbers is 3, and the average of the first and the last numbers is 4. What is the average of three numbers?

• 1] 2
• 2] 2.5
• 3] 3
• 4] 3.5

The average weight of a group of 75 girls was calculated as 47 kgs. It was later discovered that the weight of one of the girls was read as 45 kgs. Whereas her actual weight was 25 kgs. What is the actual average weight of the group of 75 girls? ( Rounded off to two digits after decimal).

• 1] 34
• 2] 36
• 3] 30
• 4] None of these

Four years ago, the average age of a family of four persons was 18 years. During this period, a baby was born. Today if the average age of the family is still 18 years, the age of the baby is

• 1] 1.2 years
• 2] 2 years
• 3] 2.5 years
• 4] 3 years

The average of four consecutive even numbers is 15. The 2nd highest number is :

• 1] 12
• 2] 18
• 3] 14
• 4] 16

David obtained 76, 65, 82, 67 and 85 marks (out of 100) in English, mathematics, physics, chemistry and biology. What are his average marks?

• 1] 65
• 2] 69
• 3] 75
• 4] None of these

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

The average of 9 observations was found to be 35. Later on, it was detected that an observation 81 was misread as 18. The correct average of the observation is -

• 1] 28
• 2] 42
• 3] 32
• 4] 45

The average weight of A, B and C is 40 kgs. Weight of C is 24 kgs more than A’s weight and 3 kgs less than B’s weight. What will be the average weight of A, B, C and D, if D weights 15 kgs less than C?

• 1] 42 kgs
• 2] 40 kgs
• 3] 36 kgs
• 4] 38 kgs

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

There are five boxes in cargo hold. The weight of the first box is 200 kg and the weight of the second box is 20% higher than the weight of the third box, whose weight is 25% higher than the first box's weight. The fourth box at 350 kg is 30% lighter than the fifth box. Find the difference in the average weight of the four heaviest boxes and the four lightest boxes.

• 1] 51.5 kg
• 2] 75 kg
• 3] 37.5 kg
• 4] 112.5 kg
• 5] None of these