<PRE><B>Question 998576</B>
Call their rates A and B.  The equations become (since rate times time = distance):
6A - 5B = 10
8B - 5A = 7 (or -5A + 8B = 7)
Now solve this system of equations...multiply appropriately to get
30A - 25B = 50
-30A + 48B = 42
When we add these we get
23B = 92 and
B = 4 km/hr
A can be found by substituting into the first equation
6A - 5(4) = 10
6A = 30
A = 5 km/hr</PRE>