A and B paint a section of wall together, A paints 30% of the total length, B paints 80 meters, the two paint the total length (11/20), how many meters is this section of wall?
甲、乙两人共同粉刷一段围墙，甲刷了全长的30%，乙刷了80米，二人共刷了全长的(11/20)，这段围墙长多少米．
<gadget id="calculator">11 / 20</gadget>
<output>11/20 = around 0.55</output>

<gadget id="calculator">30 / 100</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">(11/20) - (3/10)</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">80 / (1/4)</gadget>
<output>320</output>

<result>320</result>