SOLUTION: A shopkeeper orders a number of sunglasses for which he pays $300. As they are being unpacked, 10 get broken. By selling each sunglass at $4 more than he paid for it, he manage to

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: A shopkeeper orders a number of sunglasses for which he pays $300. As they are being unpacked, 10 get broken. By selling each sunglass at $4 more than he paid for it, he manage to       Log On


   

Question 1062294: A shopkeeper orders a number of sunglasses for which he pays $300. As they are being unpacked, 10 get broken. By selling each sunglass at $4 more than he paid for it, he manage to get a profit of $100. How many glasses did he originally order?
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
x, original quantity of sunglasses
x-10, how many actually shopkeeper did sell
p, original price for 1 sunglasses pair
300%2Fx=p, original price, again

Revenue: %28p%2B4%29%28x-10%29
Cost: 300
PROFIT: %28p%2B4%29%28x-10%29-300=100

Make the substitution for original price because that is based on the original x sunglass pairs.

highlight%28%28300%2Fx%2B4%29%28x-10%29-300=100%29

The easier part is now to just solve this equation.