Question 250229: Hello, my name is Rebecca Ghisoiu. I attend Western Govorners University, an online college. I am stuck on a few questions concerning a homework assignment, and would appreciate any feedback possible.
1) MIXTURE WORD PROBLEM
-There are 50 ounces of liquid. 12 ounces are alcohal. What percentage of the liquid is alcohal? What percentage is water?
*I have tried to solve this myself by taking the 12 ounces, turning it into a decimal (.12), and multiplying it by 50. Solution was 6% alcohal. Then, I took 12 and multiplied that by 6 which equaled 72%, the percentage of water, which is incorrect.
2) BLOOD ALCOHAL CONTENT
-I have consistently been incorrect in trying to find the BAC. I am givin a formula, and all the information needed, yet everytime I calculate the answer (in which I am told to round to the nearest thousanth) my answer is always in the negatives. If you have any advice on finding the BAC, I'd really appreciate it.
3)PERIMETER OF A RECTANGLE
-I am givin the perimeter of a rectangle, for example lets say p=64. Then, the problem will state that the length is 4cm less than twice the width. Find the length and width.
*I understand the formula for finding the lenth and width of a rectangle is P= 2L + 2W. I have trouble decoding the above sentence: "The length is 4cm less than twice the width." If you could show me an example of this, perhaps I may understand it better.
4)PERCENTAGE WORD PROBLEM
For my last question, I am having trouble with the following homework example: "College enterance exams have risen from 20.3 to 20.9 within the past year. Find the percent of this increase."
*What I have done to try to solve this problem is I find the difference (20.9-20.3) and got .6 Then, I would take .6 and divide this by the origianl number, which is 20.3; my answer rounded was 33.8% but this is incorrect. Again, I am not exactly sure what I am doing wrong here, because this is how I was taught to do this.
These four questions are actually keeping me from passing a test to continue moving forward within my math class. Any help would be wonderful, thank you for your time.
Answer by Theo(13342)   (Show Source):
You can put this solution on YOUR website! 1) MIXTURE WORD PROBLEM
-There are 50 ounces of liquid. 12 ounces are alcohol. What percentage of the liquid is alcohal? What percentage is water?
*I have tried to solve this myself by taking the 12 ounces, turning it into a decimal (.12), and multiplying it by 50. Solution was 6% alcohal. Then, I took 12 and multiplied that by 6 which equaled 72%, the percentage of water, which is incorrect.
50 ounces of liquid.
12 ounces of the 50 ounces are alcohol.
50 - 12 = 38 ounces of water and 12 ounces of alcohol.
percent of the liquid that is alcohol is 12/50 = .24 * 100% = 24%
percent of the liquid that is water is 38/50 = .76 * 100% = 76%
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3)PERIMETER OF A RECTANGLE
-I am givin the perimeter of a rectangle, for example lets say p=64. Then, the problem will state that the length is 4cm less than twice the width. Find the length and width.
*I understand the formula for finding the lenth and width of a rectangle is P= 2L + 2W. I have trouble decoding the above sentence: "The length is 4cm less than twice the width." If you could show me an example of this, perhaps I may understand it better.
p = 64.
P = 2L + 2W is correct.
length if 4cm less than twice the width means:
L = 2W - 4
substitute 2W - 4 for L and the perimeter formula becomes
64 = 2 * (2W-4) + 2W
now solve for W to get:
W = 12.
If W = 12, then L = 2W - 4 = 20
you have L = 12 and W = 20
2L + 2W = 24 + 40 = 64 so that part is good.
L = 2W-4 = 2*12 - 4 = 20 so that part is good also.
The statement "The length is 4cm less than twice the width." is decoded as follows:
4cm less than means -4.
twice the width means 2*w
put them together and you get 2*w - 4
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4)PERCENTAGE WORD PROBLEM
For my last question, I am having trouble with the following homework example: "College enterance exams have risen from 20.3 to 20.9 within the past year. Find the percent of this increase."
*What I have done to try to solve this problem is I find the difference (20.9-20.3) and got .6 Then, I would take .6 and divide this by the origianl number, which is 20.3; my answer rounded was 33.8% but this is incorrect. Again, I am not exactly sure what I am doing wrong here, because this is how I was taught to do this.
These four questions are actually keeping me from passing a test to continue moving forward within my math class. Any help would be wonderful, thank you for your time.
exams rose from 20.3 to 20.9
the difference is .6 so you got that rightg.
.6 / 20.3 is equal to .02955665 * 100% = 2.955665%
It looks to me like you did 20.3 / .6 which would be a reverse of what you should have done.
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2) BLOOD ALCOHAL CONTENT
-I have consistently been incorrect in trying to find the BAC. I am givin a formula, and all the information needed, yet everytime I calculate the answer (in which I am told to round to the nearest thousanth) my answer is always in the negatives. If you have any advice on finding the BAC, I'd really appreciate it.
you did not include the equation for this.
send it to me and I'll decipher it for you.
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