I'll ask for you, and I'll give you the answer when I get there.

Solution: Accounts receivable of two households with less than 4 tons: 1.8×(4+4)= 14.4 (Yuan).

Then these two households exceed the basic water consumption this month: (26.4- 14.4)÷3=4 (tons)

Then the water consumption of A is: (8+4) × (5/5+3) =12 × (5/8) = 7.5 (tons).

Water fee payable: 4× 1.8+(7.5-4)×3,

=7.2+ 10.5

= 17.7 (yuan)

Water fee payable by Party B: 26.4- 17.7=8.7 yuan.

Answer: Party A needs to pay 17.7 yuan water fee, and Party B needs to pay 8.7 yuan water fee.

Can it be adopted?