The honey sold in the Lai store costs 4 bottles of 50 yuan when purchased, and 3 bottles of 50 yuan when sold. If the store sells how many bottles, it can make a profit of 500 yuan.
莱商店销售的蜜糖，进货时50元4瓶，售出时50元3瓶．该店若售出多少瓶，方可获利500元．
<gadget id="calculator">50 / 3</gadget>
<output>50/3 = around 16.666667</output>

<gadget id="calculator">50 / 4</gadget>
<output>25/2 = around 12.5</output>

<gadget id="calculator">(50/3) - (25/2)</gadget>
<output>25/6 = around 4.166667</output>

<gadget id="calculator">500 / (25/6)</gadget>
<output>120</output>

<result>120</result>