Average MCQs

Practice Average MCQs with answers and detailed explanations. Learn basic average concepts, average age, marks, salary, speed, combined average, weighted average and advanced aptitude questions designed for SSC, Railway, Banking, UPSC, JKSSB, Police, Teaching and other competitive exams.

965 Total
Question #1 Report Error
The average of 5 numbers is 28. If one number is excluded, the average becomes 25. What is the excluded number?
A. 40
B. 35
C. 45
D. 30

Correct Answer: Option A


Explanation:
Sum of 5 numbers = 5 × 28 = 140. Sum of remaining 4 numbers = 4 × 25 = 100. Excluded number = 140 - 100 = 40.

This question belongs to: Maths Average
Question #2 Report Error
Find the average of first 10 natural numbers.
A. 6
B. 5
C. 6.5
D. 5.5

Correct Answer: Option D


Explanation:
Sum of first 10 natural numbers = 10×11/2 = 55. Average = 55/10 = 5.5.

This question belongs to: Maths Average
Question #3 Report Error
The average age of 6 students is 12 years. If the teacher's age is included, the average becomes 15 years. What is the teacher's age?
A. 27
B. 36
C. 33
D. 30

Correct Answer: Option C


Explanation:
Sum of 6 students' ages = 6×12=72. Sum of 7 persons = 7×15=105. Teacher's age = 105-72=33.

This question belongs to: Maths Average
Question #4 Report Error
What is the average of the squares of first 5 natural numbers?
A. 12
B. 11
C. 10
D. 9

Correct Answer: Option B


Explanation:
Squares: 1,4,9,16,25 sum=55, average=55/5=11.

This question belongs to: Maths Average
Question #5 Report Error
The average of 7 consecutive odd numbers is 15. What is the largest number?
A. 23
B. 21
C. 19
D. 17

Correct Answer: Option B


Explanation:
In consecutive odd numbers, average = middle term. So 4th number =15, largest =15+6=21.

This question belongs to: Maths Average
Question #6 Report Error
The average of 4 numbers is 25. If each number is multiplied by 3, what is the new average?
A. 100
B. 75
C. 50
D. 25

Correct Answer: Option B


Explanation:
If each number is multiplied by a constant, the average also gets multiplied by that constant. New average = 25×3=75.

This question belongs to: Maths Average
Question #7 Report Error
The average weight of 10 students is 45 kg. If a new student joins, the average becomes 46 kg. What is the weight of the new student?
A. 55 kg
B. 57 kg
C. 54 kg
D. 56 kg

Correct Answer: Option D


Explanation:
Total weight of 10 = 450. Total of 11 = 11×46=506. New student's weight = 506-450=56.

This question belongs to: Maths Average
Question #8 Report Error
Find the average of all even numbers between 1 and 20 (inclusive of 20).
A. 10.5
B. 11
C. 12
D. 10

Correct Answer: Option B


Explanation:
Even numbers: 2,4,...,20. Sum = 2+4+...+20 = 2×(1+2+...+10)=2×55=110. Count=10. Average=110/10=11.

This question belongs to: Maths Average
Question #9 Report Error
The average of 5 numbers is 40. If each number is decreased by 5, what is the new average?
A. 35
B. 45
C. 40
D. 30

Correct Answer: Option A


Explanation:
If each number is decreased by a constant, the average also decreases by that constant. New average =40-5=35.

This question belongs to: Maths Average
Question #10 Report Error
The average of 3 numbers is 18. If two of the numbers are 15 and 20, find the third number.
A. 19
B. 18
C. 17
D. 20

Correct Answer: Option A


Explanation:
Sum of 3 numbers = 3×18=54. Sum of two =15+20=35. Third =54-35=19.

This question belongs to: Maths Average