Question 1158413
<font face="Times New Roman" size="+2">


Since the cars are traveling toward each other, their combined rate of speed is the sum of their rates of speed.  Since the entire trip of 128 miles was completed in 1 hour and 36 minutes, which is to say 1.6 hours, the combined rate of speed must be:


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ r_c\ =\ \frac{128}{1.6}\ =\ 80\text{ mph}]


Let *[tex \Large r] represent the speed of the slower car, then *[tex \Large r\ +\ 10] must be the speed of the faster car, and the sum of these two quantities must be the combined speed, namely *[tex \Large 80\text{ mph}].  In short:


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ r\ +\ r\ +\ 10\ =\ 80]


Solve for *[tex \Large r] and then calculate *[tex \Large r\ +\ 10]
								
								
John
*[tex \LARGE e^{i\pi}\ +\ 1\ =\ 0]
My calculator said it, I believe it, that settles it
<img src="http://c0rk.blogs.com/gr0undzer0/darwin-fish.jpg">
*[tex \Large \ \
*[tex \LARGE \ \ \ \ \ \ \ \ \ \  
								
{{n}\choose{r}}
</font>