The average of the three numbers is 20. If two numbers are 14 and 28, then find the third number.

Correct option is A

Given:

1. The average of three numbers = 20

2. Two of the numbers are 14 and 28 .

Formula Used:

The formula for the average is:

$$\text{Average} = \frac{\text{Sum of all numbers}}{\text{Total count of numbers}}$$​

Rearranging to find the sum of all numbers:

$$\text{Sum of all numbers} = \text{Average} \times \text{Total count of numbers}$$​

The third number can be calculated as:

$$\text{Third number} = \text{Sum of all numbers} - (\text{First number} + \text{Second number})$$​

Solution:

1. Calculate the sum of all three numbers:

$$\text{Sum of all numbers} = 20 \times 3 = 60$$​

2. Calculate the third number:

Third number = 60 - (14 + 28)

Simplify:

Third number = 60 - 42 = 18