Question about MATH on Bonus exams

Need help solving #7 and #14 on Bonus Quiz #2

Reply: (by Keith)

#7, says:
How many Ml of water should be mixed with 1200 ml of at 65% solution to make a 45% solution?

a. 1733.3 mL

b. 757.8 mL

c. 533.3 mL

d. 369.2 mL

There are several ways to do this. The easiest way is probably to do an alligation, and then use proportions math to finish it. It's almost identical to This question I answered on youtube. Only, in your alligation your bottom number will be zero(water).

If you want to do the Algebra way, your setup would be like this:

(.00)X + (.65)1200 = (.45)(1200 + X)

So, #14 also, huh? OK it's kind of a brain teaser, but once you see it, it's quite easy. Lets take a look:

Which of the following formulas will produce a 1000ml solution of 3.5% amino acid in 15% dextrose?

A. Amino Acid 10% 500ml + Dextrose 30% 500ml

B. Dextrose 30% 500ml + Amino Acid 10% 300ml

C. Amino Acid 7% 500ml + Dextrose 30% 500ml

D. Dextrose 30% 600ml + Amino Acid 7% 400ml

In this question, what you have is two different solutions that will be mixed together. However, the one solution will just be diluting the other. (for both) So, then it's just like asking: "which of the available answers reflects an amount and percentage of Amino acid that could be diluted to 1000mL to make it 3.5%?" And then you see that in answer C. 500mL of 7%, if that was added to 500mL of another liquid, say, like maybe a dextrose solution, that would cut the strength in half to 3.5%. Then you do the same analysis for the Dextrose solution.

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Question about MATH on Bonus exams

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Jun 10, 2011
#7 on Bonus Quiz 2
by: kaeon103

I must be an idiot, because I am unable to solve it. I used alligation and ended up with something completely different. Could you please break down the question? I would appreciate it :)

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