Given the rationale, provide a reasonable question and answer. Step-by-step reasoning process: The sum of the bills of the family in the first 4 months is $30 / month x 4 months = $120. The sum of the bills of the family in the last 2 months is $24 / month x $2 = $48. The sum of the bills of the family over the 6 months is $120 + $48 = $168. Hence, their average monthly bill is $168 / 6 months = $28 / month.
 The question and answer:
A family's water and electricity bills average $30 a month for the first 4 months and $24 a month for the last 2 months. If the family's bills were averaged over all 6 months, what would the average monthly bill be?
The answer is 28