A ferry takes several trips between points A and B. It moves at a constant speed of 0.35 miles/minute and takes the same route on each trip. The total duration of a round trip from point A to point B and back is 80 minutes, ignoring the time spent stopped at point B. If d is the ferry’s distance from point A in miles and t is the time in minutes, which equation models the ferry’s distance from point A for the duration of the trip?
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