Interesting Question

Question

flvskidd · Answer

A child is running on a moving sidewalk in an airport. When he runs against the sidewalk's motion, he travels 
70ft
 in 
10
 seconds. When he runs with the sidewalk's motion, he travels 
110ft
 in the same amount of time. What is the rate of the child on a still sidewalk and what is the rate of the moving sidewalk?

flvskidd · Answer

Could you help me with another one after this?

wolf1728 · Answer

c - speed of child
s - speed of sidewalk

c - s = 7 ft/sec
c + s =11 ft/sec
Solve for c and s

flvskidd · Answer

c=s+7

flvskidd · Answer

c=-s+11

flvskidd · Answer

@wolf1728

mathstudent55 · Answer

Now you have c equal to two different expressions, so the expressions must be equal.
Set the two expressions in s equal to each other, and solve for s.
Then use the value of s in one of the original equations to solve for c.

wolf1728 · Answer

c - s = 7 ft/sec 
c + s =11 ft/sec
The easiest way to solve for "c" and "s" is to add both equations.