Let the four consecutive even number are x, ( x+2), (x+4), (x+6).
Clearly this is a series of consecutive even numbers
According to the formula,
Average of consecutive numbers = (first number + last number)/ 2
⇒ 27 = [x + (x + 6)]/2
⇒ x + 3 = 27
∴ x =24
∴ Greatest number = 4th consecutive even number = (x + 6) = 24 + 6 = 30
