Ben starts walking along a path at 4 mi/h. one and a half hours after ben leaves, his sister amanda begins jogging along the same path at 6 mi/h. how long will it be before amanda catches up to ben?

After 3 hours Amanda catch up to Ben.

Explanation:

Speed of Ben = 4 mi/h

Speed of Amanda = 6 mi/h

Time after Amanda starts after Ben leaves = 1.5 hours.

Let the time taken for them to catch up be t hours.

Distance traveled by Ben in time (t+1.5) = 4 * (t+1.5)

Distance traveled by Amanda in time t = 6*t

Equating both the distances

4 * (t+1.5) = 6*t

2t = 6

t = 3 hours

So after 3 hours Amanda catch up to Ben.