Question 967326: Ben was in charge of ordering 30 pizzas for the office party. He ordered three types of pizza: Cheese, pepperoni and supreme. The cheese pizza cost $7 each, the pepperoni pizza cost $10 each, and the supreme pizza cost $13 each. He spent exactly twice as much on the pepperoni pizzas as he did on the cheese pizzas. If Ben spent a total of $288 on pizza, how many pizzas did he order?
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! Ben was in charge of ordering 30 pizzas for the office party. He ordered three types of pizza: Cheese, pepperoni and supreme. The cheese pizza cost $7 each, the pepperoni pizza cost $10 each, and the supreme pizza cost $13 each. He spent exactly twice as much on the pepperoni pizzas as he did on the cheese pizzas. If Ben spent a total of $288 on pizza, how many pizzas did he order?
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Equations:
7c + 10p + 13s = 288
c + p + s = 30
7c = 2*10p
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Modify::
p = (7/20)c
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Substitute for "p"::
c + (7/20)c + s = 30
7c + 10(7/20)c + 13s = 288
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Rearrange::
(27/20)c + s = 30
(210/20)c + 13s = 288
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Modify for elimination::
(351/20)c + 13s = 390
(210/20)c + 13s = 288
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Subtract and solve for "c"::
(141/20)c = 2
141c = 40
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Note:: These equations do not result in
whole number solutions for c,p, and s.
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Cheers,
Stan H.
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