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 sum of the bills of the family in the first 4 months is $30/month x 4 months = $
<gadget id="calculator">30*4</gadget>
<output>120</output>
120.
The sum of the bills of the family in the last 2 months is $24/month x $2 = $
<gadget id="calculator">24*2</gadget>
<output>48</output>
48.
The sum of the bills of the family over the 6 months is $120 + $48 = $
<gadget id="calculator">120+48</gadget>
<output>168</output>
168.
Hence, their average monthly bill is $168/6 months = $
<gadget id="calculator">168/6</gadget>
<output>28</output>
28/month.

<result>28</result>