Question

A person on a moving walkway travels 80 ft in 40 sec. What equation represents this relationship? How many feet will the person travel in 10 sec?A. y = 1/2x; 5 ftB. y = 4x; 40 ftC. y = 2x; 20 ftD. y = 2x; 2 ft

Answer 1

We need to find which expression represents the situation given, in this case we have two values a distance (80 ft) and the elapsed time (40 s). The time is the input of the equation, it will be placed on the "x" variable and the distance is the output of the equation, it will be placed on the "y" variable. We need to find the expression that outputs "80" when we input 40. Let's check them one by one:

A.

`y=(1)/(2)\cdot40=20`

This outputs 20 ft when we input 40 s, therefore it is not this one.

B.

`y=4\cdot40=160`

This one outputs 160 ft when we input 40 s, therefore it is not this one.

C.

`y=2x=2\cdot40=80\text{ }`

This one outputs 80 ft when we input 40 s, therefore this is the correct expression.

We now need to use this expression to calculate the distance the person will travel in 10 seconds, so we will make x equal to 10 s.

`y=2\cdot10=20\text{ }`

The person will walk 20 ft.

The correct option is "C".