there is a 10 kg watermelon,95% of it is water.If we put the watermelon in t
问题描述：
there is a 10 kg watermelon,95% of it is water.If we put the watermelon in t
there is a 10 kg watermelon,95% of it is water.If we put the watermelon in the sunshine for some time,and then only 90% of it is water.Now the watermelon weighs how much ()kg 要计算过程和结果。 是不是这样的 设新西瓜重为X列方程： 10*（1-95%）=X*（1-90%） 解出X=5kg.
答
设Xg水被蒸发
（10*95%）/（10-X）=1-90%
则X=5
剩下10-5=5