SOLUTION: Can you please help me with this question? This question is for h.w that's due tomorrow and I really need help. Please do not just answer the question but show how you got to the a

Algebra ->  Numeric Fractions Calculators, Lesson and Practice -> SOLUTION: Can you please help me with this question? This question is for h.w that's due tomorrow and I really need help. Please do not just answer the question but show how you got to the a      Log On


   



Question 495481: Can you please help me with this question? This question is for h.w that's due tomorrow and I really need help. Please do not just answer the question but show how you got to the answer and all the work involved in it. Thanks so much!
Problem: Suppose you own a card shop. You buy one line of cards at a rate of 4 cards for $5. You plan to sell the cards at a rate of 3 cards for $5. How many cards must you sell in order to make a profit of $100?
Please solve with all the work as soon as possible! Thanks so much! :)

Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
Let the number of cards you need to sell be x.
Recall that Profit (P) = Selling price (S) - Cost (C).
P = S-C
The profit is to be P = $100.00
The selling price S+=+%28x%29%285%2F3%29 That is x times $5.00 per 3 cards.
The cost C+=+%28x%29%285%2F4%29 That is x times $5.00 per 4 cards.
So the equation would be:
100+=+%285%2F3%29x+-+%285%2F4%29x Solve for x.
100+=+%2820x-15x%29%2F12 Multiply both sides by 12.
1200+=+5x Divide by 5.
240+=+x
You would have to sell 240 cards to make a profit of $100.00
Check:
Selling price of 240 cards at 3 cards for $5.00 is: %28240%2F3%29%285%29+=+80%285%29=400.00 and...
The cost of 240 cards at $5.00 for 4 cards is %28240%2F4%29%285%29+=+60%285%29=300.00
P+=+S-C
P+=+400-300
P+=+100