There are 2 chefs in a small restaurant, and 3 guests come to the restaurant, and each of them ordered 2 dishes. Assume that the time for the two chefs to cook each dish is 5 minutes, and the time for the guests to eat a dish is longer than that of the chef. It takes more time to cook a dish, and what is the minimum total time for customers to wait in minutes.
一个小餐馆里有2个厨师，餐馆里来了3个客人，每人都点了2个菜，假设两个厨师做每个菜的时间都是5分钟，且客人吃一个菜的时间比厨师做一个菜的时间要多，客人等待的总时间最少是多少分钟．
<gadget id="calculator">5 * 3</gadget>
<output>15</output>

<result>15</result>