Question 894747
<i>Two cars leave towns 
d
 kilometers apart at the same time and travel toward each other. One car's rate is 
k
 kilometers per hour less than the other's. If they meet in 
h
 hours, what is the rate of the slower car?</i>


Let r = speed of faster car
r-k = speed of slower car
KNOWN:  d, k, h
UNKNOWN: r


Cars approach each other at rate of {{{r+(r-k)=highlight_green(2r-k)}}} kilometers per hour.


{{{highlight_green((2r-k)*h=d)}}}, according to uniform rates travel rule.
{{{2r-k=d/h}}}
{{{2r=d/h+k}}}
{{{r=(d/h+k)/2}}}
{{{r=(d/h+hk/h)/2}}}
{{{r=d/(2h)+hk/(2h)}}}
{{{highlight(r=(d+hk)/(2h))}}}
Exact form of formula for r can vary a bit.
Substitute given values and evaluate.