A batch of fabrics is 215 meters long, 40 suits are planted, each suit is 3.5 meters long, and the remaining fabrics are planted with 30 sets of children's clothes, how many meters of fabric is used for each suit on average.
一批布料长215米，栽40套西服，每套3.5米，剩下的布料栽30套童装，平均每套装用布料多少米．
<gadget id="calculator">3.5 * 40</gadget>
<output>140</output>

<gadget id="calculator">215 - 140</gadget>
<output>75</output>

<gadget id="calculator">75 / 30</gadget>
<output>5/2 = around 2.5</output>

<result>5/2 = around 2.5</result>