Question 181439
an orange grower has 400 crates of fruit ready and will have 20 more for each day the grower waits to sell. the present price is $60 per crate and will drop $2 per crate per day. in how many days should the grower ship the crop to maximize income?
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Revenu = price * quantity

R(x) = (60 - 2x)(400 + 20x)

R(x) = 2(30-x)*20(20+x)

R(x) = -40(x-30)(x+20)
R(x) = -40(x^2 - 10x - 600)

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Max of min occurs when x = -b/2a = 10/2 = 5 
Maximum revenue will occur on day 5
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Cheers,
Stan H.