There are a bunch of digital cards, all of which are written in multiples of 3 or 4, of which the number of cards in multiples of 3 accounts for two-thirds of the total, the number of cards in multiples of 4 accounts for three-quarters of the total, and the number of cards in multiples of 12 There are 15 cards in , so how many cards are there in total?
有数字卡一堆，写着的都是3的或4的倍数，其中3的倍数的卡数占总数三分之二，4的倍数的卡数占总数四分之三，12的倍数的卡有15张，那么共有多少张卡？
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">(3/4) - 1</gadget>
<output>-1/4 = around -0.25</output>

<gadget id="calculator">(2/3) + (-1/4)</gadget>
<output>5/12 = around 0.416667</output>

<gadget id="calculator">15 / (5/12)</gadget>
<output>36</output>

<result>36</result>