A pot of flowers is 36 yuan, buy 15 pots and get 3 pots free. Aunt Wang buys 15 pots at a time, how much is each pot cheaper?
一盆鲜花36元，买15盆送3盆．王阿姨一次买15盆，每盆便宜多少元？
<gadget id="calculator">15 + 3</gadget>
<output>18</output>

<gadget id="calculator">15 / 18</gadget>
<output>5/6 = around 0.833333</output>

<gadget id="calculator">36 * (5/6)</gadget>
<output>30</output>

<gadget id="calculator">36 - 30</gadget>
<output>6</output>

<result>6</result>