A trail mix company keeps costs down by employing the peanut

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A trail mix company keeps costs down by employing the peanuts:cashews:almonds ratio of 10:4:1 in each bag of up to 75 total nuts. What is the maximum percentage by which the company could decrease its number of peanuts per bag and still have peanuts constitute more than half the total amount of nuts?

(A) 30%
(B) 40%
(C) 49%
(D) 50%
(E) 60%

Please assist with above problem.
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by GMATGuruNY » Sat Oct 01, 2016 2:23 pm
I believe that the answer choices have been transcribed incorrectly.
When this problem was posted in 2015, the answer choices read as follows:
A trail mix company keeps costs down by employing the peanuts:cashews:almonds ratio of 10:4:1 in each bag of up to 75 total nuts. What is the maximum percentage by which the company could decrease its number of peanuts per bag and still have peanuts constitute more than half the total amount of nuts?

(A) 40%
(B) 48%
(C) 49%
(D) 50%
(E) 60%
Goal: To decrease the number of peanuts as much as possible.
Constraint: The remaining peanuts must constitute more than 1/2 of the remaining nuts.

We can PLUG IN THE ANSWERS, which represent the greatest percentage by which the number of peanuts can be decreased.
Since the total number of nuts cannot be greater than 75 -- and P : C : A = 10:4:1 = 50:20:5 -- let P=50, C=20, and A=5, for a total of 75 nuts.
Since the question stem asks for the greatest possible percentage, start with the greatest answer choice.

Answer choice E:
If the number of peanuts is reduced by 58%, we get:
New P = 50 - (58/100)(50) = 50 - 29 = 21.
New total = New P + C + A = 21+20+5 = 46.
New P/New total = 21/46, which is less than 1/2.
Since the new number of peanuts is not more than 1/2 of the new total, eliminate E.

Answer choice D:
If the number of peanuts is reduced by 50%, we get:
New P = 50 - (50/100)(50) = 50 - 25 = 25.
New total = New P + C + A = 25+20+5 = 50.
New P/New total = 25/50, which is equal to 1/2.
Since the new number of peanuts is not more than 1/2 of the new total, eliminate D.

Answer choice C.
If the number of peanuts is reduced by 49%, we get:
New P = 50 - (49/100)(50) = 50 - 49/2 = 25.5.
Since the new number of peanuts must be an integer, eliminate C.

Answer choice B:
If the number of peanuts is reduced by 48%, we get:
New P = 50 - (48/100)(50) = 50 - 24 = 26.
New total = New P + C + A = 26+20+5 = 51.
New P/New total = 26/51, which is greater than 1/2.
Success!

The correct answer is B.
Last edited by GMATGuruNY on Sun Oct 02, 2016 12:17 am, edited 2 times in total.
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by alanforde800Maximus » Sat Oct 01, 2016 9:37 pm
GMATGuruNY wrote:
alanforde800Maximus wrote:A trail mix company keeps costs down by employing the peanuts:cashews:almonds ratio of 10:4:1 in each bag of up to 75 total nuts. What is the maximum percentage by which the company could decrease its number of peanuts per bag and still have peanuts constitute more than half the total amount of nuts?

(A) 30%
(B) 40%
(C) 49%
(D) 50%
(E) 60%
Goal: To decrease the number of peanuts as much as possible.
Constraint: The remaining peanuts must constitute more than 1/2 of the remaining nuts.

We can PLUG IN THE ANSWERS, which represent the greatest percentage by which the number of peanuts can be decreased.
Since the total number of nuts cannot be greater than 75 -- and P : C : A = 10:4:1 = 50:20:5 -- let P=50, C=20, and A=5, for a total of 75 nuts.
Since the question stem asks for the greatest possible percentage, start with the greatest answer choice.

Answer choice E:
If the number of peanuts is reduced by 58%, we get:
New P = 50 - (58/100)(50) = 50 - 29 = 21.
New total = New P + C + A = 21+20+5 = 46.
New P/New total = 21/46, which is less than 1/2.
Since the new number of peanuts is not more than 1/2 of the new total, eliminate E.

Answer choice D:
If the number of peanuts is reduced by 50%, we get:
New P = 50 - (50/100)(50) = 50 - 25 = 25.
New total = New P + C + A = 25+20+5 = 50.
New P/New total = 25/50, which is equal to 1/2.
Since the new number of peanuts is not more than 1/2 of the new total, eliminate D.

Answer choice C.
If the number of peanuts is reduced by 49%, we get:
New P = 50 - (49/100)(50) = 50 - 49/2 = 25.5.
Since the new number of peanuts must be an integer, eliminate C.

Answer choice B:
If the number of peanuts is reduced by 48%, we get:
New P = 50 - (48/100)(50) = 50 - 24 = 26.
New total = New P + C + A = 26+20+5 = 51.
New P/New total = 26/51, which is greater than 1/2.
Success!

The correct answer is B.

Hello Mitch,

Thanks for reply but there is no option as 48%.

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by GMATGuruNY » Sun Oct 02, 2016 12:26 am
alanforde800Maximus wrote:Hello Mitch,

Thanks for reply but there is no option as 48%.
I believe that you (or your source) transcribed the answer choices incorrectly.
When this problem was posted in 2015 (https://www.beatthegmat.com/not-able-to- ... 81598.html), the answer choices were listed as follows:
(A) 40%
(B) 48%
(C) 49%
(D) 50%
(E) 58%
I've amended my post above to reflect the answer choices as they appeared in 2015.
As my solution shows, 48% is the greatest percentage by which the number of peanuts can be reduced.
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by Crismures » Sun Oct 02, 2016 5:43 am
Hi Mitch,
As I understand the question there are up to 75 nuts in a bag. If we reduce the number of peanuts the number of the other nuts, more exactly the cashews can increase with the same number to keep the total to 75 or less.
So if we have 75 nuts the ratio is 50:20:5
If we go with 40% option the number of peanuts will go down to 30 from 50 and the number of cashews can go up to 40 from 20 and will top the number of peanuts. 30:40:5
With 30% the number of peanuts will go down to 35 and we can get max number of cashews 35 as well.
35:35:5
I would have gone with answer choice A since 75 is the max number of nuts in the bag.

Thank you!

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by [email protected] » Sun Oct 02, 2016 9:29 am
Hi All,

This is ultimately a question about percentages. The key element to solving this question is to remember that when you remove a peanut, you CHANGE the total number of nuts in the mixture...

To maximize the percentage decrease, I want to maximize the number of nuts that I'm working with. In this way, I'm TESTing VALUES, so I'll use the numbers that would occur if the total number of nuts was 75...

Peanuts = 50
Cashews = 20
Almonds = 5

We want to remove as many peanuts as possible while still having peanuts represent MORE than half of the mixture...

The number of cashews and almonds will stay the same though, so we have 20 + 5 = 25 of those non-peanuts in total.

If we had 25 peanuts and 25 non-peanuts, then that would be 50% EXACTLY. We want MORE than 50% though, so we need to add in 1 more peanut. This gives us...

Peanuts = 26
Cashews = 20
Almonds = 5

The question asked for the decrease in the number of peanuts as a percentage. We started with 50 peanuts and removed 24 = 24/50 = 48%

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by [email protected] » Sun Oct 02, 2016 9:32 am
Hi Crismures,

The prompt tells us that the number of peanuts must constitute MORE THAN HALF of the nuts in the bag. In your examples, the number of peanuts end up being LESS than half, so those examples don't fit the 'restrictions' that the prompt described (and are thus incorrect).

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by Crismures » Sun Oct 02, 2016 4:58 pm
In my humble managerial opinion if that's the case this problem is wrong. If you just remove a number of nuts from the bags without replacing them with other nuts you will not be able to sell the bag at the same price. In my opinion the number of the nuts should remain the same or about for the purpose of still selling the bags of the nuts.
The peanuts represent 66% of the nuts in the bag. Removing 48% of the peanuts means you will have about 30% less nuts in the bag.

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by [email protected] » Sun Oct 02, 2016 5:37 pm
Hi Crismures,

While those are interesting academic points to make (from a business standpoint), they have absolutely NOTHING to do with the prompt. The prompt lays out some specific information and asks a specific question - and those are the ideas that you have to work with. As an aside, you have to be very careful about keeping you focus on the information that you've been given. In CR and RC (and the Essay), going 'off-topic' will almost certainly lead to an incorrect answer (or a low AWA score).

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by alanforde800Maximus » Mon Oct 03, 2016 8:14 am
hello Guys,

Thanks for your replies but attached the pic that contains new set of options for this problem.
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20161003_213527.jpg
Image of Problem with new options.