Question 839945: A Candy store sells red jelly beans and blue jelly beans Caden buys 8 ounces of red and 4 of blue jelly beans for a total of $20. Tovah buys 6 ounces of red and 9 of blur jelly beans for a total of $27. What is the cost per ounce for red and blue jelly beans?
Answer by josgarithmetic(39615)   (Show Source):
You can put this solution on YOUR website! Price of red jelly beans, r.
Price of blue jelly beans, b.
Price unit is dollars per ounce.
Caden's cost: 8r+4b=20
Tovah's cost: 6r+9b=27
Each of the equations can and should be simplified. Divide Caden's equation by 4, and divide Tovah's equation by 3.
Caden: 2r+b=5
Tovah: 2r+3b=9
You could use substitution to solve this system, but elimination will be easier, and maybe faster. SUBTRACT Caden equation from Tovah equation.
(2r+3b)-(2r+b)=9-5
b=4
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Finding r price of red jelly beans,
2r+b=5
2r=5-b
r=(5-b)/2
r=(5-4)/2
r=1/2 dollars per ounce, Red Jelly Beans.
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Blue Jelly Beans, $4/ounce
Red Jelly Beans, $0.50/ounce
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