A and B bought 20 books in total. If A gives B 6 books, then A will have 2 fewer books than B. How many books did B buy?
甲乙两人共买了20本书，如果甲给乙6本，那么甲就比乙少2本，乙买了多少本书？
<gadget id="calculator">6 * 2</gadget>
<output>12</output>

<gadget id="calculator">20 - 12</gadget>
<output>8</output>

<gadget id="calculator">8 + 2</gadget>
<output>10</output>

<gadget id="calculator">10 / 2</gadget>
<output>5</output>

<result>5</result>