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 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 annual income (in Rs.) of certain agricultural workers is S and that of other workers is T. The number of agricultural workers is 11 times that of other workers. Then the average monthly income (in Rs.) of all the workers is 

• 1]

  (S+T)/2

• 2]

  (S+11T)/2

• 3]

  (1/11S)+T

• 4]

  (11S+T)/12

The average age of three boys is 15 years. If their ages are in ratio 3 : 5 : 7, the age of the youngest boy is

• 1] 21 years
• 2] 18 years
• 3] 15 years
• 4] 9 years
• 5] 12 years

When the average age of a couple and their son was 42 years, the son married and got a child after one year. When the child was 5 years old, the average age of the family became 36 years. What was the age of daughter-in- law at the time of their marriage ?

• 1] 23 years
• 2] 24 years
• 3] 25 years
• 4] 26 years

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

Out of 9 persons, 8 persons spent Rs. 30 on each of their meals. The ninth one spends Rs. 20 more than the average expenditure of all the nine. The total money spent by all of them was

• 1]

  Rs 260

• 2]

  Rs 290

• 3]

  Rs 292.5

• 4]

  Rs 400.5

The average of the ages of Sumit, Krishna and Rishabh is 43 and the average of the ages of Sumit, Rishabh and Rohit is 49. If Rohit is 54 years old, what is Krishna’s age?

• 1] 24 years
• 2] 36 years
• 3] 45 years
• 4] Cannot be determined
• 5] None of these

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

3 years age, the average age of a family of 5 members was 17 years. A baby having been born, the average age of the family is same today. The present age of the baby is :

• 1]

  1 years

• 2]

  \(1\frac{1}{2} \)years

• 3]

  2 years

• 4]

  3 years