Answer:
40 miles per hour
Explanation:
Given that:
Distance = 400 miles
Without tailwind :
Time taken = 2.5 hours
Speed = distance / time
Speed = 400 miles / 2. 5
Speed = 160 miles per hour
With tail wind :
Time taken = 2 hours
Net speed = 160 + x
X. = speed of tail wind
Distance = speed * time
400 = (160 + x) * 2
400 = 320 + 2x
400 - 320 = 2x
80 = 2x
x = 40
Speed of tailwind = 40 miles per hour.