Quiz Discussion

A student finds the average of 10, 2 digits numbers. If the digits of one of the numbers interchanged, the average increases by 3.6. The difference between the digits of the 2 digits number is :

• 1] 4
• 2] 3
• 3] 2
• 4] 5

A man travels equal distances of his journey at 40, 30 and 15 km/h. respectively. Find his average speed for whole journey.

• 1] 24
• 2] 25
• 3] 27
• 4] 28

The mean weight of 34 students of a school is 42 kg. If the weight of the teacher be included, the mean rises by 400 grams. Find the weight of the teacher (in kg.)

• 1] 55 kg
• 2] 57 kg
• 3] 66 kg
• 4] 56 kg

The average of 20 students is 12 years, if the teacher's age is included, average increases by one. The age of the teacher is:

• 1] 30 years
• 2] 33 years
• 3] 28 years
• 4] 35 years

The average of five different positive numbers is 25. x is the decrease in the average when the smallest number among them is replaced by 0. What can be said about x?

• 1] x is less than 5
• 2] x is greater than 5
• 3] x is equal to 5
• 4] Cannot be determined

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 age of a family with 5 members is 28. If one of the 5 members of age 20 is excluded the average age of the family becomes -

• 1] 25
• 2] 20
• 3] 30
• 4] 24

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 weight of 21 boys was recorded as 64 kg. If the weight of the teacher was added, the average increased by 1 kg. What was the teacher’s weight?

• 1] 86 kg
• 2] 64 kg
• 3] 72 kg
• 4] 84 kg

The average of 6 numbers is 7. The average of three numbers of them is 5. What will be the average of remaining numbers?

• 1] 15
• 2] 30
• 3] 9
• 4] 42