A man flies a small airplane from Fargo to Bismarck, North Dakota --- a distance of 180 miles. Because he is flying into a head wind, the trip takes him 2 hours. On the way back, the wind is still blowing at the same speed, so the return trip takes only 1 hour 12 minutes. What is his speed in still air, and how fast is the wind blowing?
3 answers
What do you think the answer is?
120 mph
30 mph winds
30 mph winds
Let
s = still-air speed
w = wind speed
1:12 = 1 1/5 = 6/5 hours
Since distance = time * speed, you have
2(s-w) = 180
6/5 (s+w) = 180
Now solve for s and w
s = still-air speed
w = wind speed
1:12 = 1 1/5 = 6/5 hours
Since distance = time * speed, you have
2(s-w) = 180
6/5 (s+w) = 180
Now solve for s and w
1 answer