Question 1005368: A plane flies at 200 mph for the first and last half hour of a flight. It flies at a higher constant speed for the rest of the flight. The route is 2100 miles. The plane is 1000 miles from the destination 2 hours before the end of the flight. How many hours is the entire flight?
Found 2 solutions by josmiceli, MathTherapy:
Answer by josmiceli(19441)   (Show Source):
Answer by MathTherapy(10551)  (Show Source):
You can put this solution on YOUR website! A plane flies at 200 mph for the first and last half hour of a flight. It flies at a higher constant speed for the rest of the flight. The route is 2100 miles. The plane is 1000 miles from the destination 2 hours before the end of the flight. How many hours is the entire flight?
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Since the plane traveled at 200 mph for the 1st  hr of the flight, then for the 1st hour of flight, plane covered ( ) or 100 miles
Since the plane traveled at 200 mph for the last hr of the flight, then for the last hr of flight, plane covered (), or 100 miles
Since it traveled 1,000 – 100, or 900 miles,  hours before the last hour, its speed during this stretch was:  , or 600 mph
Since it’s stated that it traveled at a higher constant speed for the rest of the 2,100-mile journey, and itw’s found that its speed for 900 of
the last 1,000 miles was 600 mph, then this is the speed at which it traveled for the remaining 1,000 (2,100 – 100 – 900 – 100) miles of the journey
Therefore, time spent travelling the remaining 1,000 miles (see diagram) =  , or  hrs, or  hours
Therefore, total time for the entire trip was:  , or  hours, or 
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