Question

The average of four consecutive even numbers is 27. By adding which number does the average become 28?
1. 30
2. 29
3. 32
4. 33

Answer 1

Correct Answer - Option 3 : 32

Given:

The average of four consecutive even numbers is 27.

28 adding on each number.

Formula used:

Average = (Sum of total observations)/(Total Number of observation)

Calculation:

Let the four numbers be a, a + 2, a + 4, a + 6.

Let 'x' be added to the number then new average is 28.

(Sum of total observations) = (Total Number of observation) × Average

a + a + 2 + a + 4 + a + 6 = 27 × 4

⇒ 4a + 12 = 108 

⇒ 4a = 96

⇒ a = 24

(Sum of total observations) = (Total Number of observation) × Average

⇒ (a) + (a + 2) + (a + 4) + (a + 6) + x = 28 × 5

⇒ 4a + 12 + x = 140

⇒ 108 + x = 140 

⇒ x = 32

∴ The number added to 32 to numbers then new average is 32.