An airplane flew 3 hours with a 60 mph head wind. The return trip with a tail wind of the same speed took 2 hours. Find the speed of the plane in still air.

380 mph

340 mph

320 mph

300 mph

Question

An airplane flew 3 hours with a 60 mph head wind. The return trip with a tail wind of the same speed took 2 hours. Find the speed of the plane in still air. 

 380 mph 

 340 mph 

 320 mph 

 300 mph

anonymous · Answer

It would be 300 mph! So D

anonymous · Answer

speed = x + 60 mph
Distance = d miles
t = d / ( x + 60 ) = 2
d = 2x + 120

AGAINST wind
--------------------
speed = x - 60 mph
distance = d miles
t = d / ( x - 60 ) = 3
d = 3x - 180

2x + 120 = 3x - 180
300 = x