Question

Holly runs 7 miles per hour faster than as she walks. She runs 3 miles in the same time it takes to walk ½ mile. How fast does she walk?

Answer 1

let the speed ( walk ) = x miles/hr

then the speed ( for run) = 7miles/hr + x miles/ hr

RUN

time = t

distance = 3 miles

speed = distance/ time

(7+x) = 3 / t

t = 3 / (7+x)

WALKS

time = t

distance = 1/2 mile

speed = distance/ time

time = distance/speed

`t=(1)/(2x)`

time is the same in both instances

We say t = t

`\begin{gathered} (3)/(7+x)=(1)/(2x) \\ 6x=7+x \\ 5x=7 \\ x=(7)/(5) \\ x=1.4 \\ she\text{ }walks\text{ }at\text{ }1.4miles\text{ }per\text{ }hour \end{gathered}`