一道机经求助

晓溪

141.    １８４　There are 100 pounds of fruit and water in the fruit is 99% by weight.  After the fruit are dried and some water evaperates, water in the fruit is 98% by weight. How does the water weigh after the fruit are dried.
40 50 60,选了50

请问这道题如何计算？

baracouta

99% water make 100 pounds fruit only have 1 pound solid material in it. Let assume the water after drying weight x pound, then x/(1+x) = 0.98 so x =49. The initial weight of water is 99 pound. So 99 - 49 = 50 pounds water was vaporized.

晓溪

thanks a lot!