You are driving down highway64 and glance over, and you see you are at mile marker10 .After 30 minutes have gone by, you glance over again and you see you are now at mile marker 40. What is the average speed of your car?v =d(B)-d(A)and 1 hour = 60 minutes

T

a.60 mi/h

b.70 mi/h

c.80 mi/h

d.90 mi/h