Question 301380
<font face="Garamond" size="+2">


If the two cars went 480 km in 4 hrs, then the sum of their speeds must have been 120 km/hr.  The speed of the faster car is the speed of the slower car plus 40.  So the speed of the slower car plus the speed of the slower car plus 40 must be 120, which is to say the speed of the slower car plus the speed of the slower car must be 120 minus 40 or 80 km/hr, and then the speed of the slower car must be half of that, or 40 km/hr and the other car must have been going 40 plus 40 = 80 km/hr.



John
*[tex \LARGE e^{i\pi} + 1 = 0]
</font>