In badminton training, there are 5 male players in group A and 4 female players in group B. They are paired in mixed doubles. How many different ways are there in total?
羽毛球训练，甲组有5名男队员，乙组有4名女队员，进行男女混合双打配对，一共有多少种不同的配对方法．
<gadget id="calculator">5 * 4</gadget>
<output>20</output>

<result>20</result>