Average Aptitude Questions: Concepts, Formulas & Solved Examples

Average aptitude questions can range from simple calculations to more advanced scenarios involving groups, replacements, or real-life applications. In this section, you'll find a variety of average aptitude questions with solutions—each designed to illustrate a different type of average problem. 

Example 1: Basic Average

Question:
Find the average of 12, 15, 20, 25, and 28.

Solution:
Sum = 12 + 15 + 20 + 25 + 28 = 100
Number of values = 5
Average = 100 / 5 = 20

Example 2: Finding a Missing Value

Question:
The average age of 4 students is 18 years. If one more student joins and the average becomes 19 years, what is the age of the new student?

Solution:
Total age of 4 students = 18 × 4 = 72
Total age of 5 students = 19 × 5 = 95
Age of new student = 95 – 72 = 23 years

Example 3: Effect of Replacement

Question:
The average weight of 8 people is 60 kg. A person who weighs 65 kg leaves the group and a new person comes in which causes the average weight to drop to 59 kg. What is the weight of the new person?

Solution:
Original total = 8 × 60 = 480
New total = 8 × 59 = 472
Weight of new person = 472 – (480 – 65) = 472 – 415 = 57 kg

Example 4: Weighted Average

Question:
The question states that a class is divided into two sections. Section A has 20 students with an average score of 75, and Section B has 30 students with an average score of 80. What is the average score of the entire class?

Solution:
Total score = (20 × 75) + (30 × 80) = 1500 + 2400 = 3900
Total students = 20 + 30 = 50
Average = 3900 / 50 = 78

Example 5: Average Speed

Question:

A car travels at 60 km/h for the first half of the journey and 40 km/h for the second half. What is the average speed for the entire journey?
Solution:
Average Speed = (2 × 60 × 40) / (60 + 40) = (4800) / (100) = 48 km/h

Example 6: Error Correction

Question:
The student received an incorrect score of 85 which should have been recorded as 65. The average increased by 1 mark for a class of 20 students. What is the correct average? The incorrect score of 85 must be subtracted from the correct score of 65 to find the difference which needs to be calculated.

Solution:
Difference due to error = 85 – 65 = 20
Increase in total average = 1 × 20 = 20
So, the error explains the increase.
Correct total = (Original total with error) – 20
Correct average = (Correct total) / 20

Example 7: Average of Zero Values

Question:
The average of 10 numbers is zero. At most, how many of them can be greater than zero?

Solution:
The solution shows that if all numbers except one positive number exist then the last number must become negative because it needs to match the combined value of all positive numbers. So, at most 9 numbers can be greater than zero.

Example 8: Average of Combined Groups

Question:
The average weight of 16 boys who weigh 50.25 kg each and 8 boys who weigh 45.15 kg each. The task requires you to calculate the total weight of all the boys.

Solution:
Total weight = (16 × 50.25) + (8 × 45.15) = 804 + 361.2 = 1165.2
Total boys = 16 + 8 = 24
Average = 1165.2 / 24 = 48.55 kg

Example 9: Average Salary

Question:
The average salary which A and B together earn amounts to ₹7000. The average salary which B and C together earn amounts to ₹8500. The average salary which A and C together earn amounts to ₹9000. What is the salary of A?

Solution:
A + B = 14000
B + C = 17000
A + C = 18000
Sum: 2(A + B + C) = 49000 ⇒ A + B + C = 24500
A = 24500 – 17000 = ₹7500

Example 10: Average with Error in Marks

Question:
The student received 83 marks because the school entered incorrect data instead of his actual score of 63. His score error caused the class average to rise by 1.5 points. How many students were present?

Solution:
Difference = 83 – 63 = 20
Increase in total = 1.5 × n = 20 ⇒ n = 20 / 1.5 = 13.33 (So, likely 13 or 14 students; for exact numbers, check question context.)

Example 11: Average Age Including Teacher

Question:
The average age of 29 students together with their teacher equals 21 years. The teacher is 41 years old so what is the current average age of students?

Solution:
Total age = 30 × 21 = 630
Age of 29 students = 630 – 41 = 589
Average = 589 / 29 = 20.31 years

Example 12: Average After Adding a Value

Question:
The first five numbers have an average of 16. The new number makes the average rise to 18. What is the value of the new number?

Solution:
Sum of 5 = 5 × 16 = 80
Sum of 6 = 6 × 18 = 108
New number = 108 – 80 = 28

Example 13: Average of Consecutive Numbers

Question:
The average of the first ten natural numbers needs calculation.

Solution:
Sum = 1 + 2 + … + 10 = 55
Average = 55 / 10 = 5.5

Example 14: Average of Even Numbers

Question:
What is the average of first 8 even numbers?

Solution:
First 8 even numbers: 2, 4, …, 16
Sum = 8 × (2 + 16) / 2 = 8 × 9 = 72
Average = 72 / 8 = 9

Example 15: Average of Odd Numbers

Question:
Find the average of first 7 odd numbers.

Solution:
First 7 odd numbers: 1, 3, …, 13
Sum = 7 × (1 + 13) / 2 = 7 × 7 = 49
Average = 49 / 7 = 7

Example 16: Average of Ages with Change

Question:
The average age of 30 students is 15 years. The average age increases to 16 years when the teacher's age gets included. What is the teacher’s age?

Solution:
Total age of 30 students = 30 × 15 = 450
Total with teacher = 31 × 16 = 496
Teacher’s age = 496 – 450 = 46 years

Example 17: Average of Multiple Groups

Question:
Three numbers which have an average of 10 and two subsequent numbers which have an average of 20 produce what overall average value?

Solution:
Sum = (3 × 10) + (2 × 20) = 30 + 40 = 70
Total numbers = 5
Average = 70 / 5 = 14

Example 18: Average with Salary Increases

Question:
The five employees at the company receive an average salary of ₹6000. Two employees receive a salary increase of ₹1000. What is the new average?

Solution:
Original total = 5 × 6000 = 30000
Raise = 2 × 1000 = 2000
New total = 32000
New average = 32000 / 5 = ₹6400

Example 19: Average of Different Quantities

Question:
The grocer needs to achieve a total sales of ₹7800, ₹8200, ₹7900, ₹8600 and ₹8100 across five months. What must be the sixth month’s sale to average ₹8000?

Solution:
Total needed = 8000 × 6 = 48000
Current total = 7800 + 8200 + 7900 + 8600 + 8100 = 40600
Required = 48000 – 40600 = ₹7400

Example 20: Average of Grouped Data

Question:
The first group contains 70 students, the second group contains 75 students, the third group contains 80 students, and the fourth group contains 65 students. What is the overall average? 

Solution:
Total = (30 × 70) + (40 × 75) + (35 × 80) + (50 × 65) = 2100 + 3000 + 2800 + 3250 = 11150
Total students = 30 + 40 + 35 + 50 = 155
Average = 11150 / 155 ≈ 71.94

Example 21: Average with Replacement Error

Question:
The average of eight numbers equals 20. The new average becomes 23 when I substitute one number with 48. What was the number I replaced?

Solution:
Original total = 8 × 20 = 160
New total = 8 × 23 = 184
Difference = 184 – 160 = 24
Number replaced = 48 – 24 = 24

Example 22: Average Age Increase

Question:
The average age of a group increases by two years when a 30-year-old leaves and a new member joins the group. To find out what the new member's age is if the group consists of 10 people.

Solution:
Increase in total age = 2 × 10 = 20
So, new person’s age = 30 + 20 = 50 years

Example 23: Average with Ratio

Question:
If the ratio of three numbers to each other is 2:3:5 and their average is 200. What number is the largest of the three?

Solution:
Sum = 200 × 3 = 600
Total ratio = 2 + 3 + 5 = 10
Value of one part = 600 / 10 = 60
Largest = 5 × 60 = 300

Example 24: Average with Exclusion

Question:
The average of 11 numbers is 61. If the first six numbers have an average of 57 and the last six numbers have an average of 65, what is the value of the 6th number?

Solution:
Sum total = 11 × 61 = 671
Sum first 6 = 6 × 57 = 342
Sum last 6 = 6 × 65 = 390
Sixth value = 342 + 390 – 671 = 61

Example 25: Average Salary Distribution

Question:
Average salary of officers is ₹45000, non-officers is ₹10000, entire staff is ₹15000, and there are 20 officers. How many non-officers?

Solution:
Let non-officers = x
Total salary = (x + 20) × 15000
Officers = 20 × 45000 = 900000
Non-officers = x × 10000
900000 + 10000x = 15000x + 300000
5000x = 600000 ⇒ x = 120

Quick Recap: These examples cover all major question types, helping you apply the right formula and logic to solve average aptitude problems efficiently.

Solving average aptitude questions and answers efficiently requires more than just memorizing formulas. Here are some practical tips to help you approach these problems with accuracy and speed:

1. Understand the Question Clearly: Carefully read what is being asked—whether it’s the average, a missing value, or the effect of adding/removing an item.
2. Write Down the Relevant Formula: Start by jotting down the formula you’ll use. This helps prevent mistakes, especially in multi-step problems.
3. Check for Weighted or Grouped Data: When problems involve different populations or categories, use the weighted average formula instead of the simple average.
4. Be Mindful of Units: Make sure all values are in the same unit system (particularly relevant with speed, distance, and money).
5. Double-Check Calculations: Small errors in addition or multiplication can lead to incorrect answers. Take a moment to review your arithmetic.
6. Look for Shortcuts and Patterns: Practice spotting patterns and using shortcuts, especially with question types you see often and/or when the numbers involved are consecutive.
7. Practice Regularly: Building exposure to lots of different problems increases your familiarity with problems and your speed in solving them; use practice question banks/quizzes to test yourself.

Bottom Line: By following these tips, you’ll strengthen your ability to solve average aptitude questions quickly and accurately in any competitive exam or assessment.

Using a combination of various types of study tools can help you perform well on difficult aptitude test questions. These resources will allow you to practice specific skills in a manner that provides clear explanations, and it's easy to refer back to them when you need to be scientifically accurate. Here are some resources and study tools that will help you prepare for your exams.

Downloadable PDFs and Question Banks

• Access free or paid PDFs containing average MCQ quizzes and objective questions with answers.
• Use comprehensive solved question banks to practice a wide variety of problems.

Online Practice Quizzes and Mock Tests

• Take interactive quizzes tailored to the quantitative aptitude average questions syllabus of competitive exams.
• Attempt average mcq online test and mock tests to simulate exam conditions and assess your readiness.

Solutions and Explanations

• Review detailed solutions and step-by-step explanations for each question to understand the logic behind every answer.

Video Lectures and Tutorials

• Watch video lectures for visual learning and tips on solving average-related questions efficiently.

Syllabus and Placement Test Preparation

• Refer to curated study guides and syllabus outlines to ensure you cover all relevant topics for exams and placement tests.

The resources will help you strengthen your knowledge base while you discover your weak points and develop exam readiness for all tests that assess your average calculation skills.

Average aptitude questions are straightforward once you grasp the basics and practice regularly. Focus on understanding the underlying concepts, apply the appropriate formulas, and work through a variety of problems to enhance your skills. With consistent practice, you’ll be able to solve average-related questions quickly and accurately in any exam.

Why It Matters?

The importance of this matter needs to be explained. The process of learning average aptitude questions enables students to improve their test performance while developing better analytical skills which they can use to evaluate actual data-based situations. 

Practical Advice for Learners

• Students should practice different question types every day. 
• Students should analyze their errors to discover their most deficient skills. 
• Students need to learn essential formulas through both memorization and comprehension. 
• Students should practice mock exams to experience actual testing conditions. 
• Students need to concentrate on test management skills when they practice their tests.
• Seek out quality resources and explanations for difficult problems.