Question

This is Linear Equation. The Sum of three numbers is 27. The second number is three times the first, while the third is twice the first, Find the average.​

Answer 1

average = 9

(the third number is the average)

Explanation:

If the sum of three numbers is 27, then the average (mean) is the total (27) divided by the number of values (3):

⇒ 27 ÷ 3 = 9

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However, if you want to find the actual numbers:

Let x = first number

Let y = second number

Let z = third number

Given:

• The sum of three numbers is 27 ⇒ x + y + z = 27
• The second number is three times the first ⇒ y = 3x
• The third number is twice the first ⇒ z = 2x

Substitute y = 3x and z = 2x into x + y + z = 27 and solve for x:

⇒ x + 3x + 2x = 27

⇒ 6x = 27

⇒ x = 4.5

y = 3x

⇒ y = 3 x 4.5

⇒ y =13.5

z = 2x

⇒ z = 2 x 4.5

⇒ z = 9

Therefore, x = 4.5 y = 13.5 and z = 9

which means z (the third number) is same value as the average