Water consists of hydrogen and oxygen, and the approximate ratio, by : GMAT Problem Solving (PS)
Check GMAT Club Decision Tracker for the Latest School Decision Releases http://gmatclub.com/AppTrack

 It is currently 17 Jan 2017, 08:33

### 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

# Water consists of hydrogen and oxygen, and the approximate ratio, by

Author Message
TAGS:

### Hide Tags

Manager
Joined: 10 Dec 2007
Posts: 52
Followers: 0

Kudos [?]: 27 [0], given: 0

Water consists of hydrogen and oxygen, and the approximate ratio, by [#permalink]

### Show Tags

18 Jan 2008, 11:33
1
This post was
BOOKMARKED
00:00

Difficulty:

15% (low)

Question Stats:

77% (02:05) correct 23% (01:02) wrong based on 155 sessions

### HideShow timer Statistics

Water consists of hydrogen and oxygen, and the approximate ratio, by mass, of hydrogen to oxygen is 2:16. Approximately how many grams of oxygen are there in 144 grams of water?

(A) 16
(B) 72
(C) 112
(D) 128
(E) 142

OPEN DISCUSSION OF THIS QUESTION IS HERE: water-consists-of-hydrogen-and-oxygen-and-the-approximate-143760.html
[Reveal] Spoiler: OA
Director
Joined: 01 Jan 2008
Posts: 629
Followers: 4

Kudos [?]: 175 [0], given: 1

Re: Water consists of hydrogen and oxygen, and the approximate ratio, by [#permalink]

### Show Tags

18 Jan 2008, 11:36
portion of hydrogen in water is 2/(2+16) = 1/9.

weight of hydrogen = 144*1/9= 16.

SVP
Joined: 05 Aug 2007
Posts: 1502
Schools: NYU Stern '11
Followers: 15

Kudos [?]: 211 [0], given: 22

Re: Water consists of hydrogen and oxygen, and the approximate ratio, by [#permalink]

### Show Tags

18 Jan 2008, 11:36
H and O are in a 1:8 ratio per gram of water

Therefore, in 144 gms of water, their ratio will be 16:128

Therefore, D.

vermatanya wrote:
Water consists of hydrogen and oxygen, and the approximate ratio, by mass, of hydrogen to oxygen is 2:16. Approximately how many grams of oxygen are there in 144 grams of water?

(A)16
(B)72
(C)112
(D)128
(E)142

-thanx
Senior Manager
Joined: 28 Feb 2007
Posts: 306
Followers: 1

Kudos [?]: 40 [0], given: 0

Re: Water consists of hydrogen and oxygen, and the approximate ratio, by [#permalink]

### Show Tags

18 Jan 2008, 11:37
2
This post was
BOOKMARKED
2x+16x=18x=144
x=8
8*16=128. D.
Director
Joined: 12 Jul 2007
Posts: 862
Followers: 15

Kudos [?]: 286 [0], given: 0

Re: Water consists of hydrogen and oxygen, and the approximate ratio, by [#permalink]

### Show Tags

18 Jan 2008, 11:41
If the ratio, by mass, of hydrogen to oxygen is 2:16 then the total weight of water is 2+16=18 where oxygen is 16/18 and hydrogen makes up the other 2/18.

If we are looking at 144 grams of water let's divide it by 18.

144/18 = 48/6 = 8

So we have 8 units of water (where each unit is made up of 16 oxygen and 2 hydrogen). To find the amount of hydrogen we multiple the units of water (8) by the units of hydrogen in each unit of water (16).

16*8=128 grams of oxygen.

Manager
Joined: 10 Dec 2007
Posts: 52
Followers: 0

Kudos [?]: 27 [0], given: 0

Re: Water consists of hydrogen and oxygen, and the approximate ratio, by [#permalink]

### Show Tags

18 Jan 2008, 11:43
eschn3am wrote:
If the ratio, by mass, of hydrogen to oxygen is 2:16 then the total weight of water is 2+16=18 where oxygen is 16/18 and hydrogen makes up the other 2/18.

If we are looking at 144 grams of water let's divide it by 18.

144/18 = 48/6 = 8

So we have 8 units of water (where each unit is made up of 16 oxygen and 2 hydrogen). To find the amount of hydrogen we multiple the units of water (8) by the units of hydrogen in each unit of water (16).

16*8=128 grams of oxygen.

yeah thanx for explaining.
Manager
Joined: 10 Dec 2007
Posts: 52
Followers: 0

Kudos [?]: 27 [0], given: 0

Re: Water consists of hydrogen and oxygen, and the approximate ratio, by [#permalink]

### Show Tags

18 Jan 2008, 12:04
eschn3am wrote:
If the ratio, by mass, of hydrogen to oxygen is 2:16 then the total weight of water is 2+16=18 where oxygen is 16/18 and hydrogen makes up the other 2/18.

If we are looking at 144 grams of water let's divide it by 18.

144/18 = 48/6 = 8

So we have 8 units of water (where each unit is made up of 16 oxygen and 2 hydrogen). To find the amount of hydrogen we multiple the units of water (8) by the units of hydrogen in each unit of water (16).

16*8=128 grams of oxygen.

hey but in the end y u multiplied it with the amount of oxygen instead of hydrogen
Director
Joined: 01 Jan 2008
Posts: 629
Followers: 4

Kudos [?]: 175 [0], given: 1

Re: Water consists of hydrogen and oxygen, and the approximate ratio, by [#permalink]

### Show Tags

18 Jan 2008, 12:23
oops, i calculated the amount of hydrogen, not oxygen. I should be more careful next time.
Director
Joined: 12 Jul 2007
Posts: 862
Followers: 15

Kudos [?]: 286 [0], given: 0

Re: Water consists of hydrogen and oxygen, and the approximate ratio, by [#permalink]

### Show Tags

18 Jan 2008, 13:09
vermatanya wrote:
eschn3am wrote:
If the ratio, by mass, of hydrogen to oxygen is 2:16 then the total weight of water is 2+16=18 where oxygen is 16/18 and hydrogen makes up the other 2/18.

If we are looking at 144 grams of water let's divide it by 18.

144/18 = 48/6 = 8

So we have 8 units of water (where each unit is made up of 16 oxygen and 2 hydrogen). To find the amount of hydrogen we multiple the units of water (8) by the units of hydrogen in each unit of water (16).

16*8=128 grams of oxygen.

hey but in the end y u multiplied it with the amount of oxygen instead of hydrogen

The question is asking for the amount of oxygen. Always make sure you know exactly what the question is asking for before you answer it.
Manager
Status: GMAT Preperation
Joined: 04 Feb 2010
Posts: 103
Concentration: Social Entrepreneurship, Social Entrepreneurship
GPA: 3
WE: Consulting (Insurance)
Followers: 2

Kudos [?]: 146 [0], given: 15

Re: Water consists of hydrogen and oxygen, and the approximate ratio, by [#permalink]

### Show Tags

30 Oct 2010, 02:56
great thread .. i was getting 16 all the time .. just that i mixed up water and hydrogen
)
GMAT Club Legend
Joined: 09 Sep 2013
Posts: 13427
Followers: 575

Kudos [?]: 163 [0], given: 0

Re: Water consists of hydrogen and oxygen, and the approximate ratio, by [#permalink]

### Show Tags

12 Nov 2014, 14:07
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.
_________________
Math Expert
Joined: 02 Sep 2009
Posts: 36536
Followers: 7071

Kudos [?]: 92994 [0], given: 10541

Re: Water consists of hydrogen and oxygen, and the approximate ratio, by [#permalink]

### Show Tags

12 Nov 2014, 17:56
vermatanya wrote:
Water consists of hydrogen and oxygen, and the approximate ratio, by mass, of hydrogen to oxygen is 2:16. Approximately how many grams of oxygen are there in 144 grams of water?

(A) 16
(B) 72
(C) 112
(D) 128
(E) 142

Since the ratio, by mass, of hydrogen to oxygen is 2:16, then oxygen is 16/(2+16)=8/9 of mass of water.

Therefore there are 144*8/9=128 grams of oxygen in 144 grams of water.

OPEN DISCUSSION OF THIS QUESTION IS HERE: water-consists-of-hydrogen-and-oxygen-and-the-approximate-143760.html
_________________
Re: Water consists of hydrogen and oxygen, and the approximate ratio, by   [#permalink] 12 Nov 2014, 17:56
Similar topics Replies Last post
Similar
Topics:
1 It is well known that the ratio of hydrogen’s mass to oxygen’s mass is 7 17 Oct 2016, 23:55
6 The ratio of alcohol and water in three mixtures of alcohol and water 4 15 Feb 2016, 20:28
4 A Hydrogenator water gun has a cylindrical water tank, which is 30 10 02 Jul 2015, 00:47
2 A glucose molecule contains 6 carbon, 12 hydrogen and 6 oxygen atoms. 5 06 Jan 2015, 07:09
4 Water consists of hydrogen and oxygen, and the approximate 7 07 Dec 2012, 05:23
Display posts from previous: Sort by