Let 2N be the first even number
2N + 2 the next
2N + 4 the next
2N + 6 the last .......so we have
Average = [sum of the numbers ] / [ how many numbers we have]
17 = [ 2N + ( 2N + 2) + ( 2N + 4) + (2N + 6)] / 4 simplify
17 = [ 8N + 12] / 4 multiply both sides by 4
68 = 8N + 12 subtract 12 from both sides
56 = 8N divide both sides by 8
7 = N
So the first even number = 2(N) = 2(7) = 14
Which means that the next three are 16, 18 and 20
