Answer:
One hour after starting
Explanation:
Let Teri walk at a rate of 2 miles per hour in time , t + 0.5, since it is 30 minutes ahead and 30 minutes = 0.5 hours, the distance he moves is d = 2(t + 0.5). Also, since Cindy moves at a rate of 3 miles per hour, and starts at time t, the distance d' she moves is d' = 3t.
Now, when they catch each other, the distance moved is the same.
So, d = d'
2(t + 0.5) = 3t
expanding the brackets, we have
2t + 2 Ă— 0.5 = 3t
2t + 1 = 3t
collecting like terms, we have
3t - 2t = 1
simplifying, we have
t = 1
So, Cindy will catch Teri one hour after starting.