The school bought 5 volleyballs for a total of 325 yuan and 6 basketballs for a total of 504 yuan. How much is it cheaper to buy a volleyball than to buy a basketball?
学校买来5个排球，共花325元；还买了6个篮球，共花了504元．买一个排球比买一个篮球便宜多少元？
<gadget id="calculator">504 / 6</gadget>
<output>84</output>

<gadget id="calculator">325 / 5</gadget>
<output>65</output>

<gadget id="calculator">84 - 65</gadget>
<output>19</output>

<result>19</result>