Ben starts walking along a path at 4mi/h. One and a half hours after Ben leaves, his sister Amanda begins jogging along the same path at 7mi/h. How long will it be before Amanda catches up to Ben?

2 Hours.

Step-by-step explanation:

Ben walks 1 1/2 hours at 4 mi/h so he travels 6 miles.

Let x be the number of miles Amanda jogs so in the same time Ben has walked

x - 6 miles when Amanda catches up.

Distance = speed * time So

x = 7t (amanda)

x - 6 = 4t (Ben)

x = 4t + 6

x = 7t Therefore, as they are both equal to x:

7t = 4t + 6

3t = 6

t = 2 hours.