Patrick W. answered 04/11/15
Tutor
4.9
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Algebra and Geometry teacher
Since profits on the centerpieces are $34 and it takes 1 person-hour to make it, that's creating $34 profit/person-hour.
Since profits on the wreath are $70 and it takes 4 person-hours to make it, that's creating $17.5 profit/person-hour.
It looks like the florist would rather make as many centerpieces as possible, but we can only make 18 arrangements total.
Let's see what the math says by building some equations. I'll use w for wreaths and c for centerpieces. Because we want to use every one of the 27 hours, we can keep track of how many of those hours were used for each type of arrangement:
c+4w=27
c+w≤18
Using our first two equations, we can solve for c and substitute into the second equation
c=27-4w
(27-4w)+w≤18
27-3w≤18
Remember our rules for inequalities here: multiplying or dividing by a negative reverses the inequality.
-3w≤-9
w≥3
So the math says we must make at least 3 wreaths. We want as few wreaths as possible, so let's spend 12 hours making those 3, meaning we can spend the other 15 hours making 15 centerpieces.
3 wreaths = $210
15 centerpieces = 15*34=$510