Uncle Zhang bought 7.5 kilograms of cucumbers at the vegetable market, paid the salesperson 27 yuan, and got back 0.75 yuan. How much is cucumber per kilogram?
张叔叔在菜市场买了7.5千克的黄瓜，付给售货员27元，找回0.75元．黄瓜每千克多少元？
<gadget id="calculator">27 - 0.75</gadget>
<output>26.25</output>

<gadget id="calculator">26.25 / 7.5</gadget>
<output>3.5</output>

<result>3.5</result>