A cake recipe uses a constant ratio of 2 teaspoons vanilla : Quant Question Archive [LOCKED]
Check GMAT Club Decision Tracker for the Latest School Decision Releases http://gmatclub.com/AppTrack

 It is currently 24 Jan 2017, 06:39

### 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

# A cake recipe uses a constant ratio of 2 teaspoons vanilla

Author Message
Director
Joined: 01 May 2007
Posts: 792
Followers: 1

Kudos [?]: 287 [0], given: 0

A cake recipe uses a constant ratio of 2 teaspoons vanilla [#permalink]

### Show Tags

04 Jul 2008, 07:17
This topic is locked. If you want to discuss this question please re-post it in the respective forum.

A cake recipe uses a constant ratio of 2 teaspoons vanilla extract to 1 ounce chocolate. If the original recipe, which serves four people, is altered proportionally to yield a cake that serves six people, how many ounces of chocolate will be used in the larger cake?

1) The original recipe calls for exactly five teaspoons of vanilla extract.

2) If the original recipe were altered proportionally to yield a cake that serves eight people, ten teaspoons of vanilla extract would be used.

OA to follow. Can you please actually solve the problem to completion. I want to see how the numbers are computed. Thanks!

Last edited by jimmyjamesdonkey on 04 Jul 2008, 07:34, edited 1 time in total.
Director
Joined: 10 Sep 2007
Posts: 947
Followers: 8

Kudos [?]: 287 [0], given: 0

### Show Tags

04 Jul 2008, 07:30
Jimmy I think you have missed the number of teaspoons of vanilla in second statement. Please edit the question to put the missing information.
Director
Joined: 01 May 2007
Posts: 792
Followers: 1

Kudos [?]: 287 [0], given: 0

### Show Tags

04 Jul 2008, 07:34
Corrected the typo. thanks!
Director
Joined: 01 Jan 2008
Posts: 629
Followers: 5

Kudos [?]: 176 [0], given: 1

### Show Tags

04 Jul 2008, 07:38
the answer is D. for both cases it's (1/2)*7.5 = 3.75 oz of chocolate
Director
Joined: 01 May 2007
Posts: 792
Followers: 1

Kudos [?]: 287 [0], given: 0

### Show Tags

04 Jul 2008, 07:41
Yes, the OA is D. I was having trouble with Statement 2. The original proportion is V.E/Choc = 2/1 for 4 people. If we wanted to adjust that proportion for 8 people, we would have to double it. Would we multiply the proportion (2/1) * 2 OR would be multiply the proportion (2/1) * (2/2)???
Director
Joined: 01 Jan 2008
Posts: 629
Followers: 5

Kudos [?]: 176 [0], given: 1

### Show Tags

04 Jul 2008, 07:43
jimmyjamesdonkey wrote:
Yes, the OA is D. I was having trouble with Statement 2. The original proportion is V.E/Choc = 2/1 for 4 people. If we wanted to adjust that proportion for 8 people, we would have to double it. Would we multiply the proportion (2/1) * 2 OR would be multiply the proportion (2/1) * (2/2)???

it's either (1/2)*(1.5*5) or (1/2)*(1.5*10/2). does that help?
Director
Joined: 01 May 2007
Posts: 792
Followers: 1

Kudos [?]: 287 [0], given: 0

### Show Tags

04 Jul 2008, 07:56
Not really...We start with a ratio of 2/1 for 4 people. Statement 2, we start talking about 8 people cake, but we really want to find 6 people cake.

This is how I started to solve (for statement 2, I understand statement 1).

8 people is double 4 people...So I tried to multiply the ratio by 2. (2/1) * 2. Then I would get the amount of chocolate in a 8 person cake. Then I multiple that value by .75 to get the # of chocolate in 6 person cake. Where I botched was multiplying the ratio by 2. I found if I multiplied the numerator and denominator by 2 then this worked fine.

So I guess my question is...How do I double the ratio of 2/1? Do you have to multiply the numerator and denominator of just the numerator by 2?
Director
Joined: 12 Apr 2008
Posts: 500
Location: Eastern Europe
Schools: Oxford
Followers: 14

Kudos [?]: 221 [0], given: 4

### Show Tags

04 Jul 2008, 14:40
Quote:
Yes, the OA is D. I was having trouble with Statement 2. The original proportion is V.E/Choc = 2/1 for 4 people. If we wanted to adjust that proportion for 8 people, we would have to double it. Would we multiply the proportion (2/1) * 2 OR would be multiply the proportion (2/1) * (2/2)???

We don’t need to multiply the proportion 2 to 1. It remains the same. It’s the amount of VE and Choco that changes. So it is this amount we need to multiply.

So we have:
St 1.
2/1 = 5/(choco originally)=> choco originally = 5/2. And this amount we need to multiply by 6/4 => 5/2*6/4 = 15/4

St 2.
2/1 = 10/(choco for 8) => choco for 8 = 5. Again, multiply this by 6/8
=> 5*6/8 = 15/4.

Alternatively, you can use this logic:
2/1 = given amount/unknown amount. What the unknown amount should be in order the ration will remain 2/1?

So, for St 2.:
10 VE for eight people means that for 6 people, we need to multiply 10 by 6/8 and thus obtain the amount of VE for 6 people: VE(6) = 15/2. And the amount of Choco should be two times less than the amount of VE (this is where we use the proportion 2/1). Thus, Choco(6) = VE(6)/2 = 15/4.
VP
Joined: 03 Apr 2007
Posts: 1367
Followers: 4

Kudos [?]: 614 [0], given: 10

### Show Tags

04 Jul 2008, 17:52
Attachment:

untitled.GIF [ 12.38 KiB | Viewed 1430 times ]
Director
Joined: 01 May 2007
Posts: 792
Followers: 1

Kudos [?]: 287 [0], given: 0

### Show Tags

05 Jul 2008, 06:05

If I said double the proportion (2/1)...how would I do it...would it then be 4/1?

If I said half the proportion (2/1)...would it be 1/1?

Can anyone provide a quick blurb on adjusting proportions?
VP
Joined: 03 Apr 2007
Posts: 1367
Followers: 4

Kudos [?]: 614 [0], given: 10

### Show Tags

06 Jul 2008, 07:06
jimmyjamesdonkey wrote:

If I said double the proportion (2/1)...how would I do it...would it then be 4/1?

If I said half the proportion (2/1)...would it be 1/1?

Can anyone provide a quick blurb on adjusting proportions?

I think you are correct.
Senior Manager
Joined: 29 Mar 2008
Posts: 348
Followers: 4

Kudos [?]: 73 [0], given: 0

### Show Tags

06 Jul 2008, 08:43
-> You are correct, while doubling and halving, you multiply and divide the ratio by 2 respectively (not both numerator and denominator of the fractions)
_________________

To find what you seek in the road of life, the best proverb of all is that which says:
"Leave no stone unturned."
-Edward Bulwer Lytton

Re: Manhattan Ratios   [#permalink] 06 Jul 2008, 08:43
Display posts from previous: Sort by