Author 
Message 
TAGS:

Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 43892

A patient is given exactly 750 milliliters of a mixture of two medicat [#permalink]
Show Tags
18 Nov 2015, 22:35
Question Stats:
70% (02:06) correct 30% (02:40) wrong based on 239 sessions
HideShow timer Statistics



Verbal Forum Moderator
Status: Greatness begins beyond your comfort zone
Joined: 08 Dec 2013
Posts: 1914
Location: India
Concentration: General Management, Strategy
GPA: 3.2
WE: Information Technology (Consulting)

Re: A patient is given exactly 750 milliliters of a mixture of two medicat [#permalink]
Show Tags
19 Nov 2015, 00:00
1
This post was BOOKMARKED
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
_________________
When everything seems to be going against you, remember that the airplane takes off against the wind, not with it.  Henry Ford The Moment You Think About Giving Up, Think Of The Reason Why You Held On So Long +1 Kudos if you find this post helpful



Manager
Joined: 05 Jul 2015
Posts: 107
Concentration: Real Estate, International Business
GPA: 3.3

A patient is given exactly 750 milliliters of a mixture of two medicat [#permalink]
Show Tags
19 Nov 2015, 13:26
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



SVP
Joined: 11 Sep 2015
Posts: 2065
Location: Canada

A patient is given exactly 750 milliliters of a mixture of two medicat [#permalink]
Show Tags
19 Nov 2015, 14:22
1
This post received KUDOS
Expert's post
1
This post was BOOKMARKED
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
_________________
Brent Hanneson – Founder of gmatprepnow.com
Last edited by GMATPrepNow on 19 Nov 2015, 22:39, edited 1 time in total.



Verbal Forum Moderator
Status: Greatness begins beyond your comfort zone
Joined: 08 Dec 2013
Posts: 1914
Location: India
Concentration: General Management, Strategy
GPA: 3.2
WE: Information Technology (Consulting)

Re: A patient is given exactly 750 milliliters of a mixture of two medicat [#permalink]
Show Tags
19 Nov 2015, 18:55
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 !!
_________________
When everything seems to be going against you, remember that the airplane takes off against the wind, not with it.  Henry Ford The Moment You Think About Giving Up, Think Of The Reason Why You Held On So Long +1 Kudos if you find this post helpful



VP
Joined: 26 Mar 2013
Posts: 1441

Re: A patient is given exactly 750 milliliters of a mixture of two medicat [#permalink]
Show Tags
19 Nov 2015, 22:30
1
This post received KUDOS
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%)



SVP
Joined: 11 Sep 2015
Posts: 2065
Location: Canada

Re: A patient is given exactly 750 milliliters of a mixture of two medicat [#permalink]
Show Tags
19 Nov 2015, 22:40
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
_________________
Brent Hanneson – Founder of gmatprepnow.com



Intern
Joined: 04 Apr 2015
Posts: 3

Re: A patient is given exactly 750 milliliters of a mixture of two medicat [#permalink]
Show Tags
20 Nov 2015, 05:12
1
This post received KUDOS
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



Director
Joined: 07 Dec 2014
Posts: 907

A patient is given exactly 750 milliliters of a mixture of two medicat [#permalink]
Show Tags
07 May 2016, 14:18
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
Last edited by gracie on 06 Aug 2017, 15:58, edited 3 times in total.



NonHuman User
Joined: 09 Sep 2013
Posts: 13785

Re: A patient is given exactly 750 milliliters of a mixture of two medicat [#permalink]
Show Tags
06 Aug 2017, 01:06
Hello from the GMAT Club BumpBot! Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up  doing my job. I think you may find it valuable (esp those replies with Kudos). Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________
GMAT Books  GMAT Club Tests  Best Prices on GMAT Courses  GMAT Mobile App  Math Resources  Verbal Resources




Re: A patient is given exactly 750 milliliters of a mixture of two medicat
[#permalink]
06 Aug 2017, 01:06






