What' wrong with this?

Let S = the amount of initial grass
g = the growth rate of grass
c = the eating rate of cow
D = days for 1 cow
then
1). For 3 cows, 3*3*c = s + 3g
2). For 2 cows, 2*6*c = s + 6g
3). For 1 cow, 1*D*c = s + Dg
There is no solution for this equation system

所有跟帖： 

• 数字太高深,看不懂 -喜气连年- ♀ (0 bytes) () 05/03/2009 postreply 14:23:35

• Surprising, isn't it? What' wrong with this? -戏雨飞鹰- ♀ (0 bytes) () 05/03/2009 postreply 14:27:43

• 一头牛永远吃不完这块草！ -为了活着- ♂ (127 bytes) () 05/03/2009 postreply 17:12:06