Answer:
B. a decrease in their water bill of $3.16.
Step-by-step explanation:
Monthly service charge =$10.10
Volume charge = $1.58 for every 100 cubic feet of water.
Total monthly cost = 1.58x + 10.10
If the Johnson family used [tex]200ft^3[/tex] less water this month than last month, then they can expect a reduction in their bill by the Volume charge for [tex]200ft^3[/tex].
Volume Charge per [tex]100ft^3[/tex] of water = $1.58
Therefore: Volume Charge for [tex]200ft^3[/tex] of water = 2 X $1.58=$3.16
Therefore, the Johnson family can expect a decrease in their water bill of $3.16.