Aunt Zhang paid 40 yuan and approved a box of mineral water from the cold drink department, a total of 50 bottles. If she sells 1.2 yuan per bottle of mineral water, how much money can she make per bottle?
张阿姨付了40元，从冷饮部批回一箱矿泉水，共有50瓶．如果她每瓶矿泉水卖1.2元，每瓶能赚多少钱？
<gadget id="calculator">40 / 50</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">1.2 - (4/5)</gadget>
<output>0.4</output>

<result>0.4</result>