Average Aptitude Excersize Problems and Answers

1. The average age of 30 students of a class is 12 years. The average age of a group of 5 of the students is 10 years and that of another group of 5 of them is 14 years. What is the average age of the remaining students?
A. 8 years   
B. 12 years
C. 10 years   
D. 14 years
Ans: B
Explanation

2. The average of eight numbers is 14. The average of six of these numbers is 16. The average of the remaining two numbers is:
A. 4   
B. 16
C. 8   
D. Data inadequate
Ans: C
Explanation 

3. A motorist travels to a place 150 km away at an average speed of 50 km per hour and returns at 30 km per hour. His average speed for the whole journey in km per hour is :
A. 35   
B. 37.5
C. 37   
D. 40
Ans: B
Explanation

4. The average of 11 observations is 60. If the average of first five observations is 58 and that of the last five is 56, then the sixth observation is.
A. 90   
B. 85
C. 110   
D. 100
Ans: A
Explanation
5. The average of first five multiples of 3 is:
A. 3   
B. 8
C. 6   
D. 9
Ans: D
Explanation
6. If a, b, c, d, e are five consecutive odd numbers, their average Is:
A. 5(a + 4)   
B. 5(a+b+c+d+e)
C. abcde   
D. (a + 4)
Ans: D
Explanation
7. 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.
A. 33.25
B. 33.5
C. 34.25
D. 35
Ans: C
Explanation
8. David obtained 76, 65, 82, 67 and 85 marks (out of 100) in English, mathematics, physics, chemistry and biology. What are his average marks?
A. 65
B. 69
C. 75
D. None of above
Ans: C
Explanation
9. The average age of a husband and his wife was 23 years at the time of their marriage. After five years they have a one year old child. What is the average age of the family ?
A. 21 years
B. 20 years
C. 18 years
D. 19 years
Ans: D
Explanation
10. In a class, the average age of 30 boys is 13 years and the average of 20 girls is 12 years. what is the average age of the whole class?
A. 12.5 Yrs
B. 14.2 Yrs
C. 12.3 Yrs
D. 12.6 Yrs
E. None of these
Ans: D
Explanation
11. A man spends Rs. 1600 per month on an average for the first three months, Rs 1550 for next four months and Rs. 1800 per month for the last five months and saves Rs 5200 a year What is his average monthly income?
A. Rs. 2050
B. Rs. 2100
C. Rs. 1950
D. Rs. 2200
E. None of these
Ans: B
Explanation
12. The average age of father and his two sons is 27 Y ears. Five years ago, the average age of the two sons was 12 Y ears. If the difference between the ages of the two sons is four years, what is the present age of the father?
A. 42
B. 48
C. 44
D. 47
E. None of these
Ans: D
Explanation
13. The average of five numbers is 27. If one number is excluded, the average becomes 25. The excluded number is:
A. 25
B. 27
C. 30
D. 35
Ans: D
Explanation                     
14.  3 year ago, the average of a family of 5 members was 17 years. A baby having been born, the average age of the family is the same today. The present age of the baby is
 A. 1 year
B. 1.5 year
C. 2 year
D. 3 year
Ans: C
Explanation
15. If the average marks of three batches of 55, 60 and 45 students respectively is 50, 55 and 60, then the average marks of all the students is:
A. 53.33
B. 54.68
C. 55
D. None of these
Ans: B
Explanation