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

 It is currently 21 Oct 2019, 23:43

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

A merchant is trying to make lemonade with 20% lemon juice but he has

Author Message
TAGS:

Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 58404
A merchant is trying to make lemonade with 20% lemon juice but he has  [#permalink]

Show Tags

25 Jan 2017, 06:57
2
3
00:00

Difficulty:

25% (medium)

Question Stats:

76% (01:59) correct 24% (02:23) wrong based on 285 sessions

HideShow timer Statistics

A merchant is trying to make lemonade with 20% lemon juice but he has added too much lemon juice and now has 4 liters of a solution that is 55% lemon juice. How much water does he have to add to make the solution the correct strength?

A. 1.4 liters
B. 1.75 liters
C. 2.5 liters
D. 5.4 liters
E. 7 liters

_________________
CEO
Status: GMATINSIGHT Tutor
Joined: 08 Jul 2010
Posts: 2978
Location: India
GMAT: INSIGHT
Schools: Darden '21
WE: Education (Education)
Re: A merchant is trying to make lemonade with 20% lemon juice but he has  [#permalink]

Show Tags

25 Jan 2017, 07:10
1
1
Bunuel wrote:
A merchant is trying to make lemonade with 20% lemon juice but he has added too much lemon juice and now has 4 liters of a solution that is 55% lemon juice. How much water does he have to add to make the solution the correct strength?

A. 1.4 liters
B. 1.75 liters
C. 2.5 liters
D. 5.4 liters
E. 7 liters

Amount of lemon in 4 litres of solution = 55% of 4 lts = (55/100)*4 = 2.2 Litres

Now the needed percentage of Lemon = 20%

i.e. 2.2 should serve the purpose of 20% of the total solution

i.e. (20/100)*Total Solution = 2.2

i.e. Total Solution = 11 Litres

so the water that needs to be added = 11 - 4 = 7 Litres

_________________
Prosper!!!
GMATinsight
Bhoopendra Singh and Dr.Sushma Jha
e-mail: info@GMATinsight.com I Call us : +91-9999687183 / 9891333772
Online One-on-One Skype based classes and Classroom Coaching in South and West Delhi
http://www.GMATinsight.com/testimonials.html

ACCESS FREE GMAT TESTS HERE:22 ONLINE FREE (FULL LENGTH) GMAT CAT (PRACTICE TESTS) LINK COLLECTION
Director
Joined: 21 Mar 2016
Posts: 504
A merchant is trying to make lemonade with 20% lemon juice but he has  [#permalink]

Show Tags

25 Jan 2017, 10:52
GMATinsight
can we solve this using weighted average formula

VeritasPrepKarishma plz help
CEO
Status: GMATINSIGHT Tutor
Joined: 08 Jul 2010
Posts: 2978
Location: India
GMAT: INSIGHT
Schools: Darden '21
WE: Education (Education)
Re: A merchant is trying to make lemonade with 20% lemon juice but he has  [#permalink]

Show Tags

25 Jan 2017, 11:28
1
1
mohshu wrote:
GMATinsight
can we solve this using weighted average formula

VeritasPrepKarishma plz help

Here it is

4 Lts solution has 55% lemon and x Lts water to be added has zero percentage lemon so the equation becomes

[(55/100)*4 + (0/100)*x] / (4+x) = (20/100)

I.e. (55/100)*4 + (0/100)*x = (20/100)*(4+x)

Solving this we get x = 7 Lts.

I hope this helps.

Posted from my mobile device
_________________
Prosper!!!
GMATinsight
Bhoopendra Singh and Dr.Sushma Jha
e-mail: info@GMATinsight.com I Call us : +91-9999687183 / 9891333772
Online One-on-One Skype based classes and Classroom Coaching in South and West Delhi
http://www.GMATinsight.com/testimonials.html

ACCESS FREE GMAT TESTS HERE:22 ONLINE FREE (FULL LENGTH) GMAT CAT (PRACTICE TESTS) LINK COLLECTION
VP
Joined: 07 Dec 2014
Posts: 1224
A merchant is trying to make lemonade with 20% lemon juice but he has  [#permalink]

Show Tags

Updated on: 28 Jan 2018, 20:50
1
Bunuel wrote:
A merchant is trying to make lemonade with 20% lemon juice but he has added too much lemon juice and now has 4 liters of a solution that is 55% lemon juice. How much water does he have to add to make the solution the correct strength?

A. 1.4 liters
B. 1.75 liters
C. 2.5 liters
D. 5.4 liters
E. 7 liters

let w=liters of water to be added
.55*4=.2(4+w)
w=7 liters
E

Originally posted by gracie on 25 Jan 2017, 16:22.
Last edited by gracie on 28 Jan 2018, 20:50, edited 1 time in total.
Intern
Joined: 24 Sep 2016
Posts: 33
Location: United States (CT)
GPA: 3.81
WE: Analyst (Venture Capital)
Re: A merchant is trying to make lemonade with 20% lemon juice but he has  [#permalink]

Show Tags

25 Jan 2017, 17:58
First step convert into a fraction.
55% = 22/40 --> Every Liter is a denominator of 10.
Second step divide 22 by .2.
22/.2 --> 110 is the new denominator.
Third step subtract 110 by 40.
110-40 = 70 which equals 7 liters

Sent from my iPhone using GMAT Club Forum mobile app
Manager
Joined: 22 May 2015
Posts: 126
Re: A merchant is trying to make lemonade with 20% lemon juice but he has  [#permalink]

Show Tags

25 Jan 2017, 19:35
3
20 % is 1/5th of solution.

We have 4 Liters of Solution which has 2.2 Liters(55%) of Lemonade and 3.8 Liters of water.

Need to add x liters of water so that the lemonade becomes 1/5th of the new solution.

Hence for new solution 4+x liters will have 2.2 Liters of Lemonade and 3.8+x liters of water. Now 2.2 liters should be equal to 1/5th of 4+x liters .

So E.
_________________
Consistency is the Key
Manager
Joined: 22 May 2015
Posts: 126
Re: A merchant is trying to make lemonade with 20% lemon juice but he has  [#permalink]

Show Tags

25 Jan 2017, 19:35
1
20 % is 1/5th of solution.

We have 4 Liters of Solution which has 2.2 Liters(55%) of Lemonade and 3.8 Liters of water.

Need to add x liters of water so that the lemonade becomes 1/5th of the new solution.

Hence for new solution 4+x liters will have 2.2 Liters of Lemonade and 3.8+x liters of water. Now 2.2 liters should be equal to 1/5th of 4+x liters .

So E.
_________________
Consistency is the Key
Manager
Joined: 17 Nov 2014
Posts: 50
Location: India
Re: A merchant is trying to make lemonade with 20% lemon juice but he has  [#permalink]

Show Tags

26 Jan 2017, 00:08
2
Amount of lemon in 4 litres of solution = 55% of 4 lts = (55/100)*4 = 2.2 Litres

Amount of water in 4 litres of solution = 45% of 4 lts = (45/100)*4 = 1.8 Litres

Now the needed percentage of Lemon = 20%

i.e. 80% of the total solution will now have water. Ratio of Lemon and water now stands as (1:4)

Let us assume that X liters of water is added to arrive at this ratio:

So, 2.2/(x+1.8) = 1:4

i.e. X = 7 liters.

so the water that needs to be added = 7 Litres

_________________
Target Test Prep Representative
Affiliations: Target Test Prep
Joined: 04 Mar 2011
Posts: 2815
Re: A merchant is trying to make lemonade with 20% lemon juice but he has  [#permalink]

Show Tags

30 Jan 2017, 17:57
Bunuel wrote:
A merchant is trying to make lemonade with 20% lemon juice but he has added too much lemon juice and now has 4 liters of a solution that is 55% lemon juice. How much water does he have to add to make the solution the correct strength?

A. 1.4 liters
B. 1.75 liters
C. 2.5 liters
D. 5.4 liters
E. 7 liters

Since the merchant has 4 liters of a solution with 55% lemon juice, he has 0.55 x 4 = 2.2 liters of pure lemon juice.

We must determine how many liters of water must be added to make the solution 20% pure lemon juice.

lemon juice/total = 20% = 1/5

We can let w = the amount of water in liters that should be added to the solution. Thus:

2.2/(w + 4) = 1/5

2.2 x 5 = w + 4

11 = w + 4

7 = w

_________________

Jeffrey Miller

Jeff@TargetTestPrep.com
122 Reviews

5-star rated online GMAT quant
self study course

See why Target Test Prep is the top rated GMAT quant course on GMAT Club. Read Our Reviews

If you find one of my posts helpful, please take a moment to click on the "Kudos" button.

Manager
Joined: 22 Nov 2016
Posts: 202
Location: United States
GPA: 3.4
Re: A merchant is trying to make lemonade with 20% lemon juice but he has  [#permalink]

Show Tags

15 Oct 2017, 15:27
The question comes down to how much water should be added to increase the % of water from 45% to 80%.

$$0.45(4) + x = 0.80(4+x)$$

$$1.8 + x = 3.2 + 0.8x$$

$$0.2x = 1.4$$

$$x = 7$$

Hence, 7 liters of water must be added to increase the water content from 45% to 80%.
_________________
Kudosity killed the cat but your kudos can save it.
Manager
Joined: 04 May 2014
Posts: 151
Location: India
WE: Sales (Mutual Funds and Brokerage)
Re: A merchant is trying to make lemonade with 20% lemon juice but he has  [#permalink]

Show Tags

14 Nov 2017, 07:33
mohshu wrote:
GMATinsight
can we solve this using weighted average formula

VeritasPrepKarishma plz help

W1/W2=(A2-avg)/(avg-A1)

W1=water
W2=Lemon Juice
A2=55(lemon Juice)
A1=0(Water)
Avg=20(Required Concentration)
W1/W2=(55-20)/(20-0)=35/20=7/4 ie total sol =7+4=7 liters of water
Intern
Joined: 23 Jun 2017
Posts: 10
Re: A merchant is trying to make lemonade with 20% lemon juice but he has  [#permalink]

Show Tags

27 Jan 2018, 21:21
Bunuel wrote:
A merchant is trying to make lemonade with 20% lemon juice but he has added too much lemon juice and now has 4 liters of a solution that is 55% lemon juice. How much water does he have to add to make the solution the correct strength?

A. 1.4 liters
B. 1.75 liters
C. 2.5 liters
D. 5.4 liters
E. 7 liters

Alternative way:
1.8 + x/ 4 + x = 80/100
Solve x for water required.
Re: A merchant is trying to make lemonade with 20% lemon juice but he has   [#permalink] 27 Jan 2018, 21:21
Display posts from previous: Sort by