Question 950619
The actual rate of the plane into a head wind  is (still rate)-(wind rate)=(300mph-30mph)=270 mph .  5000 mi/270mph=18.52 hrs
ANSWER 1: With a 30 mph head wind it takes the plane 18.52 hours to fly 5000 miles.
The actual rate with a tail wind=(still rate)+(wind rate)=300mph+30mph=330mph
5000 mi/330 mph=15.15 mph
ANSWER 2: With a 30 mph tail wind it takes the plane 15.15 hours to fly 5000 miles.