# A commercial jet and a private airplane fly from Denver to Phoenix. It takes the commercial jet 1.1 hours for the flight, and it takes the private airplane 1.8 hours. The speed of the commercial jet is 210 miles per hour faster than the speed of the private airplane. Find the speed of both airplanes.

A commercial jet and a private airplane fly from Denver to Phoenix. It takes the commercial jet 1.1 hours for the flight, and it takes the private airplane 1.8 hours. The speed of the commercial jet is 210 miles per hour faster than the speed of the private airplane. Find the speed of both airplanes.
You can still ask an expert for help

• Live experts 24/7
• Questions are typically answered in as fast as 30 minutes
• Personalized clear answers

Solve your problem for the price of one coffee

• Math expert for every subject
• Pay only if we can solve it

Holly Schmidt
Le the distance to be covered be x miles speed of commercial jet ${S}_{cj}=\frac{x}{1\cdot 1}\phantom{\rule{0ex}{0ex}}x=1\cdot 1{S}_{cj}$
Speed of private plane ${S}_{pp}=\frac{x}{1.8}\phantom{\rule{0ex}{0ex}}1.1{S}_{cj}=1.8{S}_{pp}$
Given that S is 210 miles/hr faster than S_pp
Substitute
$\frac{1.8}{1.1}{S}_{pp}=210+{S}_{pp}\phantom{\rule{0ex}{0ex}}\left(1.8-1\right){S}_{pp}=210\phantom{\rule{0ex}{0ex}}\frac{7}{11}{S}_{pp}=210\phantom{\rule{0ex}{0ex}}{S}_{pp}=\frac{30×11}{7}=330\phantom{\rule{0ex}{0ex}}{S}_{cj}=210+{S}_{pp}=210+330=540$