SOLUTION: Fresh milk contains 87% water. Evaporated milk is obtained by removing some of its water, usually through heating fresh milk. A 100 kg (100 l) batch of fresh milk was being pro

Algebra ->  Percentage-and-ratio-word-problems -> SOLUTION: Fresh milk contains 87% water. Evaporated milk is obtained by removing some of its water, usually through heating fresh milk. A 100 kg (100 l) batch of fresh milk was being pro      Log On


   

Question 911070: Fresh milk contains 87% water. Evaporated milk is obtained by removing some of its
water, usually through heating fresh milk. A 100 kg (100 l) batch of fresh milk was being
processed in the factory. After 2 hours of heating, the test showed that the milk contained
80% water. What was the weight of milk at this point?
Answer by josgarithmetic(39614) About Me  (Show Source):
You can put this solution on YOUR website!
Let w be the mass in grams of water removed.
%28100%2A0.87-w%29%2F%28100-w%29=0.8

87-w=0.8%28100-w%29
87-w=80-0.8w
7-w=0.8w
7=w%2B0.8w
7=1.8w
w=7%2F1.8
w=3.9 or w=3%268%2F9

The amount of milk had become 96 grams, to the nearest whole gram value.