A moving van leaves a house traveling at an average rate of 40mi/h. The family leaves 1/2 hour later following the same route in a car. They travel at an average of 60 mi/h.

Answer 1

and then stop for dinner?

If you want to know how long the car takes to overhaul the van, then since distance = speed * time, solve for t in

40t = 60(t - 1/2)

You might even want to find the distance, but I'll leave you to that.
Next time, proofread your post. Don't make us come up with the question as well as the answer!

Answer 2

Dv = Dc.
40*0.5 + 40*t = 60 * t.
t = 1hr. to catch up.

D = V*t = 60 * 1 = 60 miles traveled by each vehicle.