Answer:
She rode her bike 20 miles... I believe this may be a trick question.
Step-by-step explanation:
Let's break down this problem...
If she is going at a rate of 5 miles per hour while walking than the maximum she could have walked in 5 hours is 25 miles.
If Angela rode her bike for 20 miles, and the got off her bike and walked "<em>the rest of the way</em>" then she should have walked 50 miles. However as we already know her rate is 5 miles per hour while walking, and therefore could only have covered half that distance in 5 hours.
Is this a multiple choice question? Is there any misssing informaation?