There are two students, A and B, and A has three times as many books as B. If B gives A 6 books, then A has 5 times as many books as B. It turns out how many books A has.
甲乙两名同学，甲的图书是乙的3倍．若乙给甲6本，则甲的图书是乙的5倍．原来甲有图书多少本．
<gadget id="calculator">6 * 5</gadget>
<output>30</output>

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

<gadget id="calculator">5 - 3</gadget>
<output>2</output>

<gadget id="calculator">36 / 2</gadget>
<output>18</output>

<gadget id="calculator">18 * 3</gadget>
<output>54</output>

<result>54</result>