Xiaohong bought 6 kilograms of pears, gave the salesperson 20 yuan, and got 5 yuan back. How much is Sydney per kilogram?
小红买了6千克雪梨，给售货员20元，找回5元．每千克雪梨多少元？
<gadget id="calculator">20 - 5</gadget>
<output>15</output>

<gadget id="calculator">15 / 6</gadget>
<output>5/2 = around 2.5</output>

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