A plane traveling from Chicago to Boston with a tailwind of 10 miles per hour takes 4 hours. The return trip in the same wind, which is now a headwind, takes the same plane 4 hours and 9 minutes. According to this problem, about how far is it from Chicago to Boston?

Answer 1

since distance = speed * time,
d = (s+10)*4
d = (s-10)*(4 9/60)
so,
4s+40 = (4 9/60)s - 10*(4 9/60)
s = 1630/3
So, d = 6640/3 mi

check:
4 * (1630/3 + 10) = 6640/3
(4 9/60) * (1630/3 - 10) = 6640/3