# PRACTICE QUESTIONS ON AVERAGES

### Examination Questions on Averages

1. The average age of 50 students and a teacher is 25 years. When the teacher’s age is excluded, the average age decreases by 1 year. What is the age of the teacher?

1. 65
2. 75
3. 74
4. 64

2. Average weight of 3 men A, B and C is 80 kg. Another man D joins the group and the average now becomes 75 kg. If another man E, whose weight is 2 kg more than that of D, replaces A then the average weight of B, C, D and E becomes 77 kg. The weight of A is:

1. 54 kg
2. 60 kg
3. 52 kg
4. 64 kg.

3. 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 age of the school is 11 years and 9 months, then the number of girls in the school is

1. 450
2. 150
3. 250
4. 350

4. Average rainfall on Monday, Tuesday, Wednesday and Thursday is 420.5 cm and average on Tuesday, Wednesday, Thursday and Friday is 440.5 cm. If the ratio of rainfall for Monday and Friday is 20:21, find the rainfall in cm for Monday and Friday.

1. 1800, 1890
2. 1682, 1762
3. 1700, 1400
4. 1600, 1680

5. A batsman makes a score of 58 runs in the 15th inning and thus increases his average by 3 runs. What is the average after 15th inning?

1. 12
2. 14
3. 16
4. 18

6. The average of 7 numbers is 8. If one number is added, their average is 9. Then the added number is

1. 12
2. 11
3. 16
4. 14

7. In a club, the average age of the members is 30 years, the average age of the male members is 34 years and that of the female members is 26 years. The percentage of male members is:

1. 50%
2. 60%
3. 30%
4. 40%

8. The average age of a jury of 5 is 40 years. If a member aged 35 resigns and a man aged 25 becomes a member, then the average age of the new jury is:

1. 30
2. 38
3. 40
4. 42

9. Average of the runs made by Raju, Shyam and Hari is 7 less than that made by Shyam, Hari and Kishore. If Kishore’s score is 35, what is Raju’s score?

1. 14
2. 21
3. 35
4. 7.

10. The average age of a group of 30 boys is 12 years. When 2 new boys join them, the average increases by 1/4 year. What is the average age (in years) of the two new boys?

1. 12
2. 13
3. 14
4. 16

11. If the average of 10% of a number, 25% of that number, 50% of that number and 75% of that is 24, then the number will be

1. 50
2. 60
3. 70
4. 80

12. The average salary of all the workers in a workshop is Rs. 8,000/-. The average salary of 7 technicians is Rs. 12,000/- and the average salary of the rest is Rs. 6,000/-. The total number of the workers in the workshop is

1. 20
2. 21
3. 22
4. 23

13. The average of 5 numbers is 27. If one number is excluded, the average becomes 25. The excluded number is

1. 25
2. 27
3. 30
4. 35