<PRE><B>Question 887381</B>
Finding rates  Two trains made the same 315-mile run.  Since one train traveled 10mph faster than the other, it arrived 2 hours earlier.  Find the speed of each train.
Let the speed of slow train is X miles per hours
speed of fast train is X+10 mile per hours 
time=distance /speed 
T1 = 315/X
t2 =315/X+10
ti-t2 = 2 (given)
315/x-315/X+10 =2
315(x+10)-315X/(x)(X+10) =2
3150/X^2+10x=2
3150 = 2x^2 +20 X   by taking 2 common on both side 
X^2 +10x-1575 =0
X^2 +45X-35X-1575=0
(X+45)(x-35)=0
X=-45 or X= 35    neglecting negative value of speed 
X=35 mile per hours and 45 mils per hours
answer 
speed will be 35,45 miles per hours 

 </PRE>