Answer:
x = 600 mph
Step-by-step explanation:
It is given that,
Speed of the jet stream = 100 mph
It travels 1200 miles in the same amount of time as it takes to fly 1000 miles against the jet stream.
We need to find the airplane's average rate in calm air. Let it is equal to x mph.
As time in same in both cases. ATQ,
[tex]\dfrac{1200}{x}=\dfrac{1000}{x-100}\\\\\dfrac{12}{x}=\dfrac{10}{x-100}\\\\12x-1200=10x\\\\12x-10x=1200\\\\2x=1200\\\\x=600[/tex]
So, the airplane's average rate in calm air is 600 mph. Hence, this is the required solution.
