Question 730190
let the speed of slower car be x 
the speed of car II = x+6

They meet after 1 hour after car I starts

distance by car I = x
distance by car II = (x+6)*3/4........... ( speed * time)

x+3/4(x+6)=92

multiply by 4
4x+3(x+6)=368

4x+3x+18=350
7x=350
x=50 

50 & 56mph