A coffee mixture has beans that sell for $0.72 a pound and beans that sell for $0.52. If 110 pounds of beans create a mixture worth $0.74 a pound, how much of each bean is used? Model the scenario then solve it. Then, in two or more sentences explain whether your solution is or is not reasonable.

Respuesta :

Let x be the number of pounds of beans that sells for $0.72 used and y be the number of pounds of beans that sells for $0.52 used. Then:
x + y = 110 . . . (1)
0.72x + 0.52y = 81.4 . . . (2)
From (1), x = 110 - y . . . (3)
Putting (3) into (2) gives
0.72(110 - y) + 0.52y = 81.4
79.2 - 0.72y + 0.52y = 81.4
79.2 - 0.2y = 81.4
0.2y = 79.2 - 81.4 = -2.2
y = -2.2/0.2 = -11
x = 110 - (-11) = 110 + 11 = 121

The solution is not reasonable because, there cannot be negative value for the number of pounds of beans used.
And 121 pounds of beans cannot produce 110 pounds.
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