Question

Sarabi drove 20 mi at 40 mph. How long did she drive?

Let d represent distance, r represent rate, and t represent time.

Answer 1

1/2 of the time

d=st
distance=speed times time
we want to find time
divide both sides by speed
d/s=t

d=20
s=40
20/40=t
1/2=t
this is in hours

she drove for 1/2 hour or 30 mins