How many plans are there to select 2 candidates from 5 candidates as representatives of mathematics class?
从5名候选人中要选出2人当数学课代表，则共多少种方案．
<gadget id="calculator">5 * 4</gadget>
<output>20</output>

<gadget id="calculator">2 * 1</gadget>
<output>2</output>

<gadget id="calculator">20 / 2</gadget>
<output>10</output>

<result>10</result>