6 students play table tennis. It takes about 5 minutes to play a game. They can play singles or doubles. How many minutes does it take for each player to play a game? How about two rounds each?
6名同学打乒乓球，打一局约要5分钟，可以单打，也可以双打．每人打一局，至少需要多少分钟？每人打两局呢？
<gadget id="calculator">5 * 3</gadget>
<output>15</output>

<result>15</result>