Find all School-related info fast with the new School-Specific MBA Forum

 It is currently 05 Jul 2015, 14:08

### 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

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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# I need help with a simple math question

Author Message
TAGS:
Intern
Joined: 21 Jun 2008
Posts: 4
Followers: 0

Kudos [?]: 0 [0], given: 0

I need help with a simple math question [#permalink]  18 Feb 2009, 06:21
I am having difficulty with the following question and do have the answer, but am uncertain as how to arrive there:

There are x gallons of 1% milk, y gallons of 2% milk, and z gallons of 3% milk. If one created the combination of x+y+Z to yield 1.5% milk, what's x in terms of y and z?

The answer happens to be y+3z

Could someone please help me in terms of the steps to get this answer (it seems simple, but I am having a mind block).

THANKS!
Senior Manager
Joined: 08 Jan 2009
Posts: 329
Followers: 2

Kudos [?]: 91 [0], given: 5

Re: I need help with a simple math question [#permalink]  18 Feb 2009, 06:53
0.01x+0.02y+0.03z = 0.015( x + y + z)

Assume y = 40 and x =60

0.01x+ 0.8 +1.8 = .015( x+ 100)

simplifying this X = 220.

When u subsititute y and z in the eqn x= y+3z =220.
Manager
Joined: 17 Dec 2008
Posts: 179
Followers: 1

Kudos [?]: 64 [0], given: 0

Re: I need help with a simple math question [#permalink]  18 Feb 2009, 07:01
Similar eqn. but don't substitute numbers here(else you need to evaluate all 5 answers).
(x + 2y + 3z) /100 = 1.5(x+y+z)/100
=> x + 2y + 3z = 1.5(x+y+z)
=> 2x + 4y + 6z = 3x+3y+3z (both sides x 2)
=> 4y + 6z -3y -3z = x
=> x = y + 3z
Re: I need help with a simple math question   [#permalink] 18 Feb 2009, 07:01
Similar topics Replies Last post
Similar
Topics:
Math Questions I need help on 3 28 Feb 2009, 14:01
1 I need help on math questions 1 21 Jun 2008, 17:01
5 Math Questions from GMATPrep that I need help 1 30 Jul 2007, 16:22
I need help with some Math questions!!!!!!! 4 04 Apr 2007, 15:52
help needed on math questions 6 01 Aug 2006, 11:03
Display posts from previous: Sort by