How many different selection methods are there to select two program hosts (one male and one female) from 20 boys and 25 girls?
从20名男生和25名女生中选出两位节目主持人(男、女生各一名)，共有多少种不同的选法．
<gadget id="calculator">20 * 25</gadget>
<output>500</output>

<result>500</result>