Question 782907
12 minutes is {{{12/60}}} hour, {{{1/5}}} of an hour.


The sum of the walking distances done must be 1.5 miles.

one rate is r and the other rate is {{{r+1/2}}}.

The time that each friend walks is the same, h, in hours.
{{{r*t=d}}} basic idea
 

{{{r*h+(r+1/2)*h=1.5}}}
We know that h=1/5 hour, so substitute this:
{{{highlight(r*(1/5)+(r+1/2)(1/5)=1.5)}}}
Try doing all as decimals.
{{{r(0.2)+(r+0.5)(0.2)=1.5}}}
{{{0.2r+0.2r+0.10=1.5}}}
{{{0.4r=1.5-0.10}}}
{{{0.4r=1.4}}}
{{{r=1.4/0.4}}}
{{{r=14/4=7/2}}}
{{{highlight(r=3.5)}}} miles per hour
The other friend walks at 4.5 miles per hour.