1.

The average of three consecutive numbers is 27. Find the new average when all three numbers are decreased by 3 each.1. 242. 283. 264. 30

Answer» Correct Answer - Option 1 : 24

Given :

The average of three consecutive numbers is 27.

Calculation :

Let the first number be x

The second number = (x + 1)

The third number = (x + 2)

A.T.Q.

(x + x 1 + x + 2)/3 = 27

⇒ (3x + 3) = 27 × 3

⇒ 3x + 3 = 81

⇒ 3x = 78

⇒ x = 26

First number = 26

Second number = 27

Third number = 28

Now,

Each number is decreased by 3

First new number = 26 - 3 = 23

Second new number = 27 - 3 = 24

Third new number = 28 - 3 = 25

⇒ New average = (23 + 24 + 25)/3

⇒ New average = 72/3

⇒ New average = 24

∴ the required new average is 24

Short tricks :

If each number is decreased or increased by the given number the average will also decrease or increase by the given number.

Each number is decreased by 3 so, the average will also decrease by 3.

Given average = 27

Each number is decreased by 3 

⇒ New average = 27 - 3

∴ The required new average is 24.


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