Introduction to Average

 

Definition of Average:

An average is a value that represents the central or typical value of a set of numbers. It is calculated by dividing the sum of all values in the set by the total number of values.

Formula for Average:

$$\text{Average}=\frac{\text{Sum of all values}}{\text{Total number of values}}$$

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Examples of Average:

Example 1: Finding the Average of Numbers

Find the average of 4, 8, and 12.

Solution:

$$\text{Sum}=4+8+12=24$$$$\text{Total numbers}=3$$$$\text{Average}=\frac{24}{3}=8$$

So, the average is 8.

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Example 2: Finding the Average Speed

A person travels 60 km in 2 hours and then 90 km in 3 hours. Find the average speed.

Solution:

$$\text{Total Distance}=60+90=150\text{ km}$$$$\text{Total Time}=2+3=5\text{ hours}$$$$\text{Average Speed}=\frac{150}{5}=30\text{ km/h}$$

So, the average speed is 30 km/h.

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Multiple Choice Questions (MCQs)

1. What is the average of 10, 20, and 30?
   a) 15
   b) 20
   c) 25
   d) 30

   Answer: b) 20

2. If a student scores 80, 85, and 90 in three subjects, what is the average score?
   a) 85
   b) 80
   c) 90
   d) 75

   Answer: a) 85

3. If the average of five numbers is 50, what is their total sum?
   a) 200
   b) 250
   c) 300
   d) 350

   Answer: b) 250

4. A car travels 120 km in 3 hours and 180 km in 3 hours. What is the average speed?
   a) 40 km/h
   b) 50 km/h
   c) 60 km/h
   d) 70 km/h

   Answer: c) 60 km/h

5. What is the average of first five natural numbers (1, 2, 3, 4, 5)?
   a) 2
   b) 3
   c) 4
   d) 5

   Answer: b) 3