GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 19 Oct 2019, 18:08

Close

GMAT Club Daily Prep

Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Close

Request Expert Reply

Confirm Cancel

A patient is given exactly 750 milliliters of a mixture of two medicat

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Find Similar Topics 
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 58445
A patient is given exactly 750 milliliters of a mixture of two medicat  [#permalink]

Show Tags

New post 18 Nov 2015, 23:35
15
00:00
A
B
C
D
E

Difficulty:

  55% (hard)

Question Stats:

69% (02:33) correct 31% (02:51) wrong based on 317 sessions

HideShow timer Statistics

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

_________________
Most Helpful Expert Reply
GMAT Club Legend
GMAT Club Legend
User avatar
V
Joined: 12 Sep 2015
Posts: 4009
Location: Canada
A patient is given exactly 750 milliliters of a mixture of two medicat  [#permalink]

Show Tags

New post Updated on: 19 Nov 2015, 23:39
5
2
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/805

Cheers,
Brent
_________________
Test confidently with gmatprepnow.com
Image

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.
General Discussion
Verbal Forum Moderator
User avatar
V
Status: Greatness begins beyond your comfort zone
Joined: 08 Dec 2013
Posts: 2401
Location: India
Concentration: General Management, Strategy
Schools: Kelley '20, ISB '19
GPA: 3.2
WE: Information Technology (Consulting)
GMAT ToolKit User Reviews Badge CAT Tests
Re: A patient is given exactly 750 milliliters of a mixture of two medicat  [#permalink]

Show Tags

New post 19 Nov 2015, 01:00
1
1
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
Manager
Manager
User avatar
Joined: 05 Jul 2015
Posts: 93
Concentration: Real Estate, International Business
GMAT 1: 600 Q33 V40
GPA: 3.3
A patient is given exactly 750 milliliters of a mixture of two medicat  [#permalink]

Show Tags

New post 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

A----------given--------B
300--------215-------150
-----85----------65-----

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)(750-B)+(1/5)B = 215
300-(2/5)B + (1/5)B = 215
(-1/5)B = -115
B=575 WRONG!!!!!!! Please Help
Verbal Forum Moderator
User avatar
V
Status: Greatness begins beyond your comfort zone
Joined: 08 Dec 2013
Posts: 2401
Location: India
Concentration: General Management, Strategy
Schools: Kelley '20, ISB '19
GPA: 3.2
WE: Information Technology (Consulting)
GMAT ToolKit User Reviews Badge CAT Tests
Re: A patient is given exactly 750 milliliters of a mixture of two medicat  [#permalink]

Show Tags

New post 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

A----------given--------B
300--------215-------150
-----85----------65-----

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)(750-B)+(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
SVP
SVP
User avatar
V
Joined: 26 Mar 2013
Posts: 2344
Reviews Badge CAT Tests
Re: A patient is given exactly 750 milliliters of a mixture of two medicat  [#permalink]

Show Tags

New post 19 Nov 2015, 23:30
1
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/805

Cheers,
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%)
GMAT Club Legend
GMAT Club Legend
User avatar
V
Joined: 12 Sep 2015
Posts: 4009
Location: Canada
Re: A patient is given exactly 750 milliliters of a mixture of two medicat  [#permalink]

Show Tags

New post 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/805

Cheers,
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
_________________
Test confidently with gmatprepnow.com
Image
Intern
Intern
avatar
Joined: 04 Apr 2015
Posts: 3
Re: A patient is given exactly 750 milliliters of a mixture of two medicat  [#permalink]

Show Tags

New post 20 Nov 2015, 06:12
1
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
VP
VP
avatar
P
Joined: 07 Dec 2014
Posts: 1224
A patient is given exactly 750 milliliters of a mixture of two medicat  [#permalink]

Show Tags

New post 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.
Non-Human User
User avatar
Joined: 09 Sep 2013
Posts: 13275
Re: A patient is given exactly 750 milliliters of a mixture of two medicat  [#permalink]

Show Tags

New post 13 Aug 2019, 02:37
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 Club Bot
Re: A patient is given exactly 750 milliliters of a mixture of two medicat   [#permalink] 13 Aug 2019, 02:37
Display posts from previous: Sort by

A patient is given exactly 750 milliliters of a mixture of two medicat

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  





Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne