<PRE><B>Question 525347</B>
Car I 40 mph
Car II 55 mph

they are moving in same direction
so effective speed = 15 mph
distance =10 miles

Time = distance/speed
time = 10/15
time = 2/3 hours

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Let t be the time taken by Car A
d= 40t

Car B - speed = 55
(d+10)= 55t
substitute d in the second equation

40t+10=55t
55t-40t=10
15t=10
t=10/15
t=2/3 hours</PRE>