It is currently 17 Dec 2018, 03:41

### 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

# i dont know what im missing

Author Message
TAGS:
Intern
Joined: 22 Oct 2016
Posts: 15
Followers: 0

Kudos [?]: 3 [0], given: 0

i dont know what im missing [#permalink]  03 Jan 2017, 11:44
00:00

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
in 750 gram of mixture of salt and water , there is 30% of water. how much water should be converted to steam so that water in the mix remains 25%?

i think the answer should be 11.25

bcas, 225gms is 30% of 750gms. 5% of 225gms is 11.25gms which should be evoporated.

what am i missing?

Brief me, if tthere is a concept behind this.

thanks.
GMAT Club Legend
Joined: 07 Jun 2014
Posts: 4750
GRE 1: Q167 V156
WE: Business Development (Energy and Utilities)
Followers: 93

Kudos [?]: 1664 [1] , given: 396

Re: i dont know what im missing [#permalink]  03 Jan 2017, 13:40
1
KUDOS
Expert's post
ssiva wrote:
in 750 gram of mixture of salt and water , there is 30% of water. how much water should be converted to steam so that water in the mix remains 25%?

i think the answer should be 11.25

bcas, 225gms is 30% of 750gms. 5% of 225gms is 11.25gms which should be evoporated.

what am i missing?

Brief me, if tthere is a concept behind this.

thanks.

Hi,

Rule: PERCENTAGES are not your friends

Now given that 750 gms of water contains 30% water or $$\frac{30}{100}\times 750$$ grams of water or $$225$$ grams of water.

Let x grams of water be evaporated such that the solution now contains 25% water.

$$\frac{225 - x}{750 -x}=25%$$.

or $$\frac{225 - x}{750 -x}=\frac{1}{4}$$.

or $$(225 -x)\times 4 = 750 -x$$.

or $$3x = 150$$ or $$x=50$$ gms

Hence 50 grams of water needs to be evaporated.
_________________

Sandy
If you found this post useful, please let me know by pressing the Kudos Button

Try our free Online GRE Test

Re: i dont know what im missing   [#permalink] 03 Jan 2017, 13:40
Display posts from previous: Sort by