Question 545110:  A vendor sold 200 tickets for an upcoming rock concert. Floor seats were $36 and stadium seats were $28. The vendor sold $6080 in tickets. How many $36 and $28 tickets did the vendor sell? 
 Answer by lmeeks54(111)      (Show Source): 
You can  put this solution on YOUR website! Let f = # of floor seat tickets sold 
Let s = # stadium seat tickets sold 
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Given: 
total of 200 tickets sold 
floor tickets cost $36 
stadium tickets cost $28 
value of all tickets sold = $6,080 
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f + s = 200 
36f + 28s = 6080 
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Two equations and two unknowns.  Let's rewrite the 1st equation solving for one variable in terms of the other and then substitute that identity into the 2nd equation: 
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subtract s from both sides: 
f = 200 - s 
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substitute this into the 2nd equation: 
36(200 - s) + 28s = 6080 
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no we have one equation and one unknown, which we can easily solve: 
7200 - 36s + 28s = 6080 
7200 - 8s = 6080 
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add 8s and subtract 6080 from both sides to simplify: 
7200 - 6080 - 8s + 8s = 6080 - 6080 + 8s 
1120 = 8s 
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divide both sides by 8: 
s = 140, which is the # of stadium seats sold. 
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Let's go back to the f = 200 - s identity to find out how many floor tickets were sold: 
f = 200 - s 
f = 200 - 140 
f = 60, which is the # of floor tickets sold. 
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Let's check our work with the value equation: 
36f + 28s = 6080 
36(60) + 28(140) = 6080 
2160 + 3920 = 6080 
6080 = 6080 checks 
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The vendor sold 60 floor tix @ $36 ea + 140 stadium tix @ $28 ea. 
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cheers, 
Lee 
 
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