Need help on math word problem

Question

two airplanes depart from an airport traveling in opposite directions. the second airplane is 200 mph faster than the first. after 2 hours they are 1100 miles apart. find the speed of the airplanes

Answer 1

This involves the formula: distance = rate x time

 

let plane 1 travel a distance of x miles

 

plane 2 travels a distance of (1100 - x) miles

 

the rate of plane 1 is y

 

the rate of plane 2 is (y + 200)

 

Of course, the time is 2 hours based on the info given in the problem

 

x = y(2) = 2y

 

(1100 - x) = (y + 200)(2)

 

1100 - x = 2y + 400

 

1100 - 2y = 2y + 400 (using substitution of x = 2y)

 

1100 = 4y + 400

 

700 = 4y

 

175 = y

 

Plane 1 travels at a rate of 175 mi/hr and 

 

Plane 2 travels at a rate of y + 200 = 175 + 200 = 375 mi/hr