SOLUTION: A store sells 90 ski jackets for $200 dollars each. A survey indicates that for each $10 decrease in price, five more jackets will be sold. a) Find the number of jackets sold and

Question 1039486: A store sells 90 ski jackets for $200 dollars each. A survey indicates that for each $10 decrease in price, five more jackets will be sold.
a) Find the number of jackets sold and the selling price, when the total revenue is $17 600
b) What is the lowest price the will give revenues of at least 15 600? How many jackets would be sold at this price?
Answer by Aldorozos(172) (Show Source): You can put this solution on YOUR website!
(90+5x)(200-10x) = 17600
Therefore
-50x^2 +100x +1800 = 17600
We divide both sides by -50
x^2 -2x -8 = 0 This is quadratic equation x = 4. This means that we have dropped the price four times. Which means 4 *10 = 40 Therefore the price = 200-40 = 160 and we have sold 4*5 + 90 jackets which is 110
To see if we have done it correctly we multiply 110* 160 and we get 17600
We solve the second part of the problem the same way and we get x=8
This means we have dropped the price 8 times which is 8*10 = 80. This means the price has to be 200 - 80 = 120
and the number of jackets should be 90+ 8*5 = 130

RELATED QUESTIONS
A clothing store sells 140 jackets in a season for $15 each. The manager determined that... (answered by Theo)

A sporting goods store sells 90 fishing rods in a season for $200 each. Each $10 decrease (answered by ikleyn,MathTherapy)

A Grocery store sells 4000 bags ( 4 litres each) of milk per week when the price is $5.50 (answered by FrankM)

A sport store sells about 50 mountain bikes per month at a price of $220 each. For each... (answered by richwmiller)

A store sells about 80 sweaters per month at a price of $ 30. For each $ 1 decrease in... (answered by josmiceli)

1. A garment store sells about 40 t-shirts per week at a price Php 100 each, 10 decrease... (answered by Boreal)

A pair of shoes on sale is labelled 20% off the marked price. If the shoes were priced at (answered by rfer)

I need help setting up this word problem...I have tried several approaches and none of... (answered by scott8148)