There is a dry well. It took a snail 40 minutes to climb from the bottom of the well to the top of the well at 8 a.m., rested at the top of the well for 20 minutes, climbed from the top of the well to the bottom of the well, took another 40 minutes, rested for another 20 minutes, and climbed up again. To the mouth of the well. So uninterrupted climbing up and down. An ant crawled from the mouth of the well to the bottom of the well at 8 am, and immediately crawled from the bottom of the well to the mouth of the well, and then climbed from the mouth of the well to the bottom of the well. So uninterrupted climbing up and down. Suppose it takes 20 minutes for ants to climb from the wellhead to the bottom of the well, and 40 minutes each time to go from the bottom of the well to the wellhead. By 6 pm, how many times have they met in total?
有一口枯井，一只蜗牛上午8时从井底开始用了40分钟爬到井口，在井口休息了20分钟后又从井口爬到井底，也用了40分钟，再休息20分钟又向上爬向井口．如此不间断的爬上爬下．一只蚂蚁，上午8时从井口爬到井底，并立即从井底爬向井口，再从井口爬到井底．如此不间断的爬上爬下．假设蚂蚁从井口爬到井底每次都用20分钟，从井底到井口每次都用40分钟，到了下午6时，他们一共相遇多少次？
<gadget id="calculator">5 * 3</gadget>
<output>15</output>

<result>15</result>