Answer:
The rate of jet in still air is 850 mile per hour
The rate of jetstream is 150 mile per hour.
Step-by-step explanation:
Given as :
The distance cover against jetstream = 5600 miles
The time taken against Jetstream = 8 hours
The distance cover with jetstream = 4000 miles
The time taken with the jetstream = 4 hours
Now , let The speed of jet in still air = x mph
The speed of jetstream = y mph
As , Speed = 
So, According to question
x - y =
Or, x - y = 700 mph
x + y = 
Or, x + y = 1000 mph
So, ( x - y ) + ( x + y ) = 700 + 1000
Or, 2 x = 1700
∴ x =
= 850 mph
And y = 1000 - 850 = 150 mph
Hence The rate of jet in still air is 850 mile per hour and The rate of jetstream is 150 mile per hour. Answer