whats the average speed of each plane ?

Question

Two planes leave from Atlanta, Georgia. One makes a 7

hr flight to Seattle, Washington, and the other makes a 3

hr flight to Boston, Massachusetts. The plane to Boston averages 52mph

slower than the plane to Seattle. If the total distance traveled by both planes is 3124mi

, determine the average speed of each plane.

Answer 1

distance = speed times time

d= rt

3124 = 7B + 3S where B= the plane to Boston's speed and S = plane to Seattle's speed in miles per hour

= 7B +3(B+52) Seattle plane is 52 mph faster

3124 = 7B + 3B + 156

10B = 3124 -156 = 2988

B= 2988/10 = 298.8 mph

S = 299.8+52 = 350.8 mph