The price of a basketball is 60 yuan, and the price of a volleyball is that of a basketball (17/20). How much is a volleyball cheaper than a basketball?
一个篮球的标价是60元，一个排球的标价是篮球的(17/20)．一个排球比一个篮球便宜多少钱？
<gadget id="calculator">17 / 20</gadget>
<output>17/20 = around 0.85</output>

<gadget id="calculator">1 - (17/20)</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">60 * (3/20)</gadget>
<output>9</output>

<result>9</result>