<PRE><B>Question 53951</B>
tickets for a train $120 for sleeping room $80 for berth and $50 for coach 
:
the total sales were $8600
:
Let s = no. of sleeping rms; Let b = no. of berths; Let c = no. of coaches 
:
If there were 20 more berth than sleeping
            b = s + 20
:
 and 3 time as many coach as sleeping
                 c = 3s
:
 how many of each type were sold.
:
   120s + 80b + 50c = 8600
:
Substitute (s+20) for b; and 3s for c; in above eq, and solve for s 
:
This should help you.

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