Residential tap water charges are as follows: each household uses less than 4 tons of water per month, 1.8 yuan per ton, and when it exceeds 4 tons, the excess is 3 yuan per ton. In a certain month, two households, A and B, pay a total of 26.4 yuan for water, and the ratio of water consumption is 5:3, so how much should B pay for water?
居民自来水收费标准如下：每户每月用水4吨以下，每吨1.8元，当超过4吨时，超过部分每吨3元．某月甲、乙两户共交水费26.4元，用水量之比是5：3，则乙应交水费多少元．
<gadget id="calculator">4 + 4</gadget>
<output>8</output>

<gadget id="calculator">1.8 * 8</gadget>
<output>14.4</output>

<gadget id="calculator">26.4 - 14.4</gadget>
<output>12</output>

<gadget id="calculator">12 / 3</gadget>
<output>4</output>

<gadget id="calculator">4 * 1.8</gadget>
<output>7.2</output>

<gadget id="calculator">4 + 4 + 4</gadget>
<output>12</output>

<gadget id="calculator">5 + 3</gadget>
<output>8</output>

<gadget id="calculator">3 / 8</gadget>
<output>3/8 = around 0.375</output>

<gadget id="calculator">12 * (3/8)</gadget>
<output>9/2 = around 4.5</output>

<gadget id="calculator">(9/2) - 4</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(1/2) * 3</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">7.2 + (3/2)</gadget>
<output>8.7</output>

<result>8.7</result>