Suppose one sheep eats one unit of grass per day. Then 10 sheep eat 200 units in 20 days and 15 sheep eat 150 units in 15 days. This mean grass growth rate is 5 units per day, and originally there are 100 units on the ground. Now 25 sheep eats 25 units per day, and minus 5 units growth, so grass reduces at 20 units per day. 5 days it reaches 0.www.ddhw.com
哈哈哈哈 O(∩_∩)O哈哈~ 好久不来了，不小心看了一眼自己主页，发现自动关联了自己以往发过的帖，点进这个看了一眼，笑个半死。。。敢情我当初还发过这么搞笑的东西啊，我自己完全不记得了 
雷达卡
发表于 2005-3-10 21:38:38