The price of Type A toothbrush is 13.5 yuan for 5 pieces, and the price of Type B toothbrush is "buy 5, get 2 free", the price is 17.5 yuan, and you can buy 35 pieces of the same toothbrush. How much is each cheaper?
甲种牙刷的售价是5支13.5元，乙种牙刷是"买5赠2"，售价是17.5元，买同种牙刷35支，买哪种牙刷更便宜？每支便宜多少钱？
<gadget id="calculator">35 / 5</gadget>
<output>7</output>

<gadget id="calculator">13.5 * 7</gadget>
<output>94.5</output>

<gadget id="calculator">94.5 / 35</gadget>
<output>2.7</output>

<gadget id="calculator">35 / 7</gadget>
<output>5</output>

<gadget id="calculator">17.5 * 5</gadget>
<output>87.5</output>

<gadget id="calculator">87.5 / 35</gadget>
<output>2.5</output>

<gadget id="calculator">2.7 - 2.5</gadget>
<output>0.2</output>

<result>0.2</result>