Question 950176
A plane flies at 180 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 2090 miles.
:
 "The plane is 990 miles from the destination 2 hours before the end of the flight."
From this information we can find the higher speed. 
The last half hour at 180 mph covers 90 mile, therefore it took 1.5 hrs to fly 900 mile
{{{900/1.5}}} = 600 mph
:
 How many hours is the entire flight in hours?
1 hr to go 180 mi, 2090 - 180 = 1910 mi at 600 mph
{{{1910/600}}} + 1 = 4.1833 hrs or 4 + .1833(60) = 4 hrs 11 minutes
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