Rusty the Rhino was very thirsty, despite the fact that water made up 85% of his body weight. After drinking a considerable amount of water, Rusty weighted 1350 pounds, and water made up 86% of his body weight.

What was Rusty's weight before he had his drink?

What was the weight of the water he drank?

I am not sure how to do this problem, but this is what I have so far.

I multiplied 1350 by .14 to find out how much of his weight was not water. I got 189. I subtracted 1350 from 189 to get how much of his weight is water. I do not know if I am on the right track. I am lost. Please help

You are on the right track. Regardless of how much water he drinks, his weight without water should remain the same! Keep going!

Even simpler than that.
Now much has the % changed from before and after?

It is changed 1"%.

You're really close

You know that he weights 189 pounds without any water. Which is 15% of his original weight so...