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A patient is given exactly 750 milliliters of a mixture of two medicat [#permalink]
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18 Nov 2015, 23:35
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Re: A patient is given exactly 750 milliliters of a mixture of two medicat [#permalink]
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19 Nov 2015, 01:00
Let there be A milliliters of Medication A and B milliliters of Medication B A+B = 750  1 Medication A contains 40% pain killer and medication B contains 20% pain killer. (40/100)*A + (20/100)*B = 215 => (2/5)*A + (1/5)*B = 215 Multiplying by 5 , we get 2A + B = 1075  2 Equation 2 Equation 1 , we get A = 325 B = 425 Answer D
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A patient is given exactly 750 milliliters of a mixture of two medicat [#permalink]
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19 Nov 2015, 14:26
I tried algebra first but messed up and didn't get an answer choice so then I used this method but I'm not sure if it's the quickest. I probably took 3 minutes because of my mess up.
If mixture was all A it would be (2/5)750= 300 If it was all B the mixture would be (1/5)(750) = 150
AgivenB 300215150 8565
85+65=150 so B is (85/150)(750) = 85*5 = 425
My algebra looked like this. Could someone tell me where I went wrong?
A+B = 750 (2/5)A+(1/5)B=215
(2/5)(750B)+(1/5)B = 215 300(2/5)B + (1/5)B = 215 (1/5)B = 115 B=575 WRONG!!!!!!! Please Help



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A patient is given exactly 750 milliliters of a mixture of two medicat [#permalink]
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Updated on: 19 Nov 2015, 23:39
Bunuel wrote: A patient is given exactly 750 milliliters of a mixture of two medications daily. Medication A contains 40% pain killer and medication B contains 20% pain killer. If the patient receives exactly 215 milliliters of pain killer daily, how many milliliters of medication B are in the mixture?
A. 150 B. 225 C. 325 D. 425 E. 550 Medication A: 40% pain killer Medication B: 20% pain killer We combine medications to get TOTAL of 750 ml that's approximately 29% pain killer (215/750 ≈ 29%) Important, if we combine EQUAL AMOUNTS of medications A and B (i.e., 375 mls of each), the TOTAL mixture is 30%. Since the ACTUAL mixture is 29% , we know that this mixture has MORE of medication B (20%) than medication A (40%) However, since 29% is very close to 30%, we know that a BIT MORE than half the mixture is medication B. Check the answer choices to see that D (425) is a bit more than half. Answer: D For more on this concept, please see our free video on weighted averages  http://www.gmatprepnow.com/module/gmat ... /video/805Cheers, Brent
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Originally posted by GMATPrepNow on 19 Nov 2015, 15:22.
Last edited by GMATPrepNow on 19 Nov 2015, 23:39, edited 1 time in total.



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Re: A patient is given exactly 750 milliliters of a mixture of two medicat [#permalink]
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19 Nov 2015, 19:55
DJ1986 wrote: I tried algebra first but messed up and didn't get an answer choice so then I used this method but I'm not sure if it's the quickest. I probably took 3 minutes because of my mess up.
If mixture was all A it would be (2/5)750= 300 If it was all B the mixture would be (1/5)(750) = 150
AgivenB 300215150 8565
85+65=150 so B is (85/150)(750) = 85*5 = 425
My algebra looked like this. Could someone tell me where I went wrong?
A+B = 750 (2/5)A+(1/5)B=215
(2/5)(750B)+(1/5)B = 215 300(2/5)B + (1/5)B = 215 (1/5)B = 115  you made an error here B=575 WRONG!!!!!!! Please Help [/b] Hi DJ1986 , 300(2/5)B + (1/5)B = 215 => (1/5)B = 215  300 = 85 =>B = 425 Hope this helps !!
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Re: A patient is given exactly 750 milliliters of a mixture of two medicat [#permalink]
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19 Nov 2015, 23:30
GMATPrepNow wrote: Bunuel wrote: A patient is given exactly 750 milliliters of a mixture of two medications daily. Medication A contains 40% pain killer and medication B contains 20% pain killer. If the patient receives exactly 215 milliliters of pain killer daily, how many milliliters of medication B are in the mixture?
A. 150 B. 225 C. 325 D. 425 E. 550 Medication A: 40% pain killer Medication B: 20% pain killer We combine medications to get TOTAL of 750 ml that's approximately 29% pain killer (215/750 ≈ 29%) Important, if we combine EQUAL AMOUNTS of medications A and B (i.e., 375 mls of each), the TOTAL mixture is 30%. Since the ACTUAL mixture is 29% , we know that this mixture has MORE of medication A (20%) than medication B (40%)However, since 29% is very close to 30%, we know that a BIT MORE than half the mixture is medication B. Check the answer choices to see that D (425) is a bit more than half. Answer: D For more on this concept, please see our free video on weighted averages  http://www.gmatprepnow.com/module/gmat ... /video/805Cheers, Brent Hi Brent, Really nice logic solution. However, I think there is type error. Please review the highlighted part. it should be Medicine B (20%) and A (40%)



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Re: A patient is given exactly 750 milliliters of a mixture of two medicat [#permalink]
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19 Nov 2015, 23:40
Mo2men wrote: GMATPrepNow wrote: Bunuel wrote: A patient is given exactly 750 milliliters of a mixture of two medications daily. Medication A contains 40% pain killer and medication B contains 20% pain killer. If the patient receives exactly 215 milliliters of pain killer daily, how many milliliters of medication B are in the mixture?
A. 150 B. 225 C. 325 D. 425 E. 550 Medication A: 40% pain killer Medication B: 20% pain killer We combine medications to get TOTAL of 750 ml that's approximately 29% pain killer (215/750 ≈ 29%) Important, if we combine EQUAL AMOUNTS of medications A and B (i.e., 375 mls of each), the TOTAL mixture is 30%. Since the ACTUAL mixture is 29% , we know that this mixture has MORE of medication A (20%) than medication B (40%)However, since 29% is very close to 30%, we know that a BIT MORE than half the mixture is medication B. Check the answer choices to see that D (425) is a bit more than half. Answer: D For more on this concept, please see our free video on weighted averages  http://www.gmatprepnow.com/module/gmat ... /video/805Cheers, Brent Hi Brent, Really nice logic solution. However, I think there is type error. Please review the highlighted part. it should be Medicine B (20%) and A (40%) Good catch, Mo2men! I have edited my response. Cheers, Brent
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Re: A patient is given exactly 750 milliliters of a mixture of two medicat [#permalink]
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20 Nov 2015, 06:12
Bunuel wrote: A patient is given exactly 750 milliliters of a mixture of two medications daily. Medication A contains 40% pain killer and medication B contains 20% pain killer. If the patient receives exactly 215 milliliters of pain killer daily, how many milliliters of medication B are in the mixture?
A. 150 B. 225 C. 325 D. 425 E. 550 Total mixture = 750 mL Milliliters of medication B in the mixture = B Milliliters of medication A in the mixture = (750  B) Medication A contains 40% pain killer, B contains 20% pain killer, and the patient receives 215 mL. 0.4 (750  B) + 0.2 (B) = 215 300  0.4*B + 0.2*B = 215 0.2*B = 85 B = 425 Answer D



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A patient is given exactly 750 milliliters of a mixture of two medicat [#permalink]
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Updated on: 06 Aug 2017, 16:58
A patient is given exactly 750 milliliters of a mixture of two medications daily. Medication A contains 40% pain killer and medication B contains 20% pain killer. If the patient receives exactly 215 milliliters of pain killer daily, how many milliliters of medication B are in the mixture?
A. 150 B. 225 C. 325 D. 425 E. 550
equation1: A+B=750 ml equation2: .4A+.2B=215 ml multiplying e2 by 2.5, A+.5B=537.5 ml subtracting from equation1, .5B=212.5 ml B=425 ml D
Originally posted by gracie on 07 May 2016, 15:18.
Last edited by gracie on 06 Aug 2017, 16:58, edited 3 times in total.



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Re: A patient is given exactly 750 milliliters of a mixture of two medicat [#permalink]
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