Question 723260
A helicopter leaves the air station going 180 mph. 30 minutes later an airplane leaves going 330 mph. How many minutes until the airplane catches up with the helicopter?

I set it up as 180x=330(x-30).
Solve for x, see if it's right.
180x = 330x - 990
-150x = -990
x = 99/15 = 6.6 hours
Seems like a long time.
----------------------
30 mins = 0.5 hours
d = r*t = 180*0.5 --> the helicopter is 90 miles away when the plane starts
---
The plane "gains on" the h/c at 150 mi/hr (330 - 180)
t = d/r = 90/150
t = 0.6 hours
t = 36 minutes