Answer: 7 miles
Explanation:
To get the length of the route use the expression for speed,
Distance = Speed × Time
Length of the route is 7 miles.
It's given in the question,
Speed of Tomas and Tasha initially = 3.5 mph
Therefore, distance travelled by both with the speed of 2 mph one way will be,
Distance = 3.5t [Here, t = time ]
Speed of both while coming back = 2 mph
And the time taken = t + (1 hour 30 minutes)
= (t + 1.5) hours
Therefore, distance travelled while coming back = Speed × Time
= 2(t + 1.5)
Since, length of the route is same both ways,
3.5t = 2(t + 1.5)
3.5t = 2t + 3
3.5t - 2t = 3
1.5t = 3
t = 2 hours
Now substitute the value of t in the expression to get the distance of the route,
Distance = 3.5t
= 3.5 × 2
= 7 miles
Therefore, route was 7 miles long.