Answer:
5 miles
Step-by-step explanation:
Set it up in terms of x. She'll run x miles on Tuesday, x miles on Thursday, and 3x miles on Saturday. If she runs 25 miles in a week (even though she can run more, we're only concerned with minimums in this problem), then 25 = x + x + 3x. This can be simplified down into 25 = 5x. All you need to do here is isolate x by dividing both sides by 5 to get x = 5. Don't forget your units! (:
