An airplane flew 3 hours with a 40 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.

Question

ganpat · Answer

head wind is against.. so addition, while tail wind is along so subtraction..

speed = distance/ time
40 = d/ 3
d= 120 miles..

while Return , 

speed = d/ time
s= 120/2
s= 60mph

averages speed = 2 (xy)/ (x+y) = 2 (40 * 60)/ 100 =  48mph...

this might be answer.. cross check with ur options...

anonymous · Answer

thanks a lot!!!

ganpat · Answer

what do option say ??

anonymous · Answer

oh yea, the options are 180 miles, 200 miles, 220 likes, and 240 miles

ganpat · Answer

40 =  s+ w
60 = s-w 

so 2s = 100 

s= 50 mph.. speed pf plane in still air..