Aflyer on a reconnaissance flight has 4 hours for a round trip. his blade can fly 200 mph in still air. he flies out from his base against a 20 mph wind and immediately returns to his base, flying with the same wind. how many hours did he take for his fight out?

When flying with the wind, the effective plane speed is 200 + 20 = 220 mph.
When flying against the wind, the effective plane speed is 200 - 10 = 180 mph.

Let d =  the distance (miles) from his base to the destination.
The time (hours) to travel with the wind is
t₁ = d/220  
The time (hours) to travel against the wind is
t₂ = d/180

The total time taken is 4 hours, therefore
t₁ + t₂ = 4
d/220 + d/180 = 4
d(1/220 + 1/180) = 4
0.010101d = 4
d = 396 miles

Therefore
t₁ = 396/220 = 1.8 hours = 1 hour, 48 minutes (floght in)
t₂ = 396/180 = 2.2 hours = 2 hours, 12 minutes (flight out)

2.2 hours

the formula of a slope:

from a table we have

substitute:

the slope of f(x) is -1.

the graph of funcfion g(x) is a horizontal line. the slope of a horizontal line is equal 0. therefore the slope of g(x) is 0.

-1 < 0

answer: the function g(x) has the greatest slope.