Answer:
12 hours
Step-by-step explanation:
21 miles - 4 hours
63 miles - x hours
x = 63 x 4/21 = 12 hours
12 hours-
21/4=5.25
5.25x12=63
z < ¾
Or z < 0.75
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i actually dont know about any of this im just trying to make this answer 20 characters long