<p>I will be continually posting questions on this thread should I come across a problem I cannot understand the answer to. </p>
<p>I will start off with two math questions:</p>
<ol>
<li>A factory produces b TVs per hour. Of this number produced each hour, c have 20-inch screens and the rest have 24-inch screens. In terms of b and c, how many hours does it take the factory to make 200 24-inch screen TVs?</li>
</ol>
<p>A. 200/(b-c)
B.100/c
C. 200/(bc)
D (b+c)/200
E. 200bc</p>
<p>The answer is A. This was a question from Maximum SAT by Pete Edwards. </p>
<ol>
<li>Gift certificates were sold by an ice-cream parlor in the month of July. Each gift certificate was worth either $2, $3, or $5. Twice as many $2 gift certificates were sold as $3 gift certificates, and twice as many $3 gift certificates were sold as $5 gift certificates. The total value of all the gift certificates sold was $57. How many $3 gift certificates were sold in July?</li>
</ol>
<p>The answer is 6, but I don't know how to arrive at 6. If you explain this, please explain it step-by-step since I will have a hard time interpreting some of your simplified steps. I looked this question on recent threads but could not understand.</p>
<p>Thanks!</p>
<p>For the first one, try plugging numbers in so it’s easier to move the figures around. The factory produces ten (b) TVs per hour. Of these ten, two © have 20inch screens. </p>
<p>With the above problem, it’s easy to figure out how many hours it takes to make 200 24inch TVs.</p>
<p>Here’s the logical procession:</p>
<p>How many 24inch TVs are produced in one hour? Easy, 10-2=8. So (b-c)</p>
<p>So how many hours does it take to make 200 of them? They make 8 in one hour. I would divide 200 by 8. That gives you 25 hours. AKA 200/(b-c) which is your answer. </p>
<p>Oh, alright thanks! I understand now. :)</p>
<p>Here is the detailed explanation for your 2nd question.</p>
<p>Let number of $5 gift certificates be x.
As, twice as many $3 gift certificates were sold as $5 gift certificates, Number of $3 gift certificates be 2x.
As, twice as many $2 gift certificates were sold as $3 gift certificates, Number of $2 gift certificates be 4x.
As, the total value of all the gift certificates sold was $57. We write this as the equation: $2<em>(4x) + $3</em>(2x) + $5<em>(x) =57
8x + 6x + 5x = 57
9x = 57
x=3
Number of $3 gift certificates were sold in July are 2x=2</em>3=6
Hope this helps.</p>
<p>Thanks! I understand now after several days of confusion!</p>