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Each of the cucumbers in 100 pounds of cucumbers is composed
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Each of the cucumbers in 100 pounds of cucumbers is composed of 99% water, by weight. After some of the water evaporates, the cucumbers are now 98% water by weight. What is the new weight of the cucumbers, in pounds? (A) 2 (B) 50 (C) 92 (D) 96 (E) 98
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Originally posted by shrive555 on 06 Oct 2010, 11:52.
Last edited by hazelnut on 12 Sep 2018, 18:37, edited 2 times in total.
Edited the question




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Re: Each of the cucumbers in 100 pounds of cucumbers is composed
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06 Oct 2010, 12:01




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Re: Each of the cucumbers in 100 pounds of cucumbers is composed
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06 Oct 2010, 17:43
My approach
Before evaporation by weight
100 pounds of Cucumber = 99 pounds water + 1 pound cucumber matter
After evaporation
lets say the weight of cucumber is x then by weight
x = (98/100* x is water) + 1 pound of cucumber matter
solving for x gives 50




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Re: Each of the cucumbers in 100 pounds of cucumbers is composed
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08 Oct 2010, 02:45
Nice explanation Bunuel



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Re: Each of the cucumbers in 100 pounds of cucumbers is composed
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30 Jan 2011, 11:43
Hi Bunnel, Would it be possible explain your solution? For some reason I am not getting it that how cucumber will be 50 pound after reduction of 1% water. Thanks



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Re: Each of the cucumbers in 100 pounds of cucumbers is composed
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30 Jan 2011, 12:20



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Re: Each of the cucumbers in 100 pounds of cucumbers is composed
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12 May 2012, 02:57
shrive555 wrote: Each of the cucumbers in 100 pounds of cucumbers is composed of 99% water, by weight. After some of the water evaporates, the cucumbers are now 98% water by weight. What is the new weight of the cucumbers, in pounds?
A. 2 B. 50 C. 92 D. 96 E. 98 Responding to a pm: There are two ways of getting to the answer here. Method 1: Let's go forward to back. Say we have 98% mixture (2% pure cucumber extract and 98% water). Say, we also have plain water (100% water). If we mix these two, we get 100 pounds of 99% mixture (1% pure cucumber extract and 99% water). We want to find the amount of pure water that was mixed. (Usually, we are given two components and we have to mix them. This question does the opposite. It separates out the components of the mixture but overall it doesn't matter to us at all.) w1/w2 = (A2  Aavg)/(Aavg  A1) = (100  99)/(99  98) = 1/1 The 98% mixture and the pure water must have been mixed in 1:1 ratio. Since total mixture is 100 pounds, the amount of pure water must be 50 pounds and the 98% mixture must have been 50 pounds. Answer (B) Method 2: Another way to think about this problem: The amount of pure cucumber extract stays the same. Only the amount of water reduces. The amount of pure cucumber extract was 1 pound in the 99% mixture and it stayed 1 pound in the 98% mixture. In 100 pounds of 99% cucumber mix, this pure cucumber extract was 1% and in 98% cucumber mix, this same pure cucumber extract was 2% of the cucumber mix. Say, the total weight of 98% cucumber mix is x pounds. 1 pound = (2/100)*x x = 50 pounds The answer is a little unintuitive since you don't expect so much water to disappear to just make it go down from 99% to 98% but instead, think that you need to make the amount of pure cucumber extract to go up from 1% to 2% i.e. you need it to double in proportion. For the same amount (1 pound) to be double in proportion, you need to reduce the total weight by half.
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Re: Each of the cucumbers in 100 pounds of cucumbers is composed
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13 Jun 2013, 03:09



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Re: Each of the cucumbers in 100 pounds of cucumbers is composed
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18 Apr 2014, 23:02
I don't think any formula is needed in such questions.
It is pure logic which governs these questions.
Approach:
When one thing is getting replaced or removed just CONCENTRATE on the CONCENTRATION of that thing.
Concentrate here on 'Water'
99 Pounds = Water 1 pound = non water
Let X be evaporated so that concentration changes to 98%
99  X = Water in new thing = 98% of total
99X = 98/100 (100  X)
X=50



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Re: Each of the cucumbers in 100 pounds of cucumbers is composed
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20 Apr 2014, 20:55
TGC wrote: I don't think any formula is needed in such questions.
It is pure logic which governs these questions.
Approach:
When one thing is getting replaced or removed just CONCENTRATE on the CONCENTRATION of that thing.
Concentrate here on 'Water'
99 Pounds = Water 1 pound = non water
Let X be evaporated so that concentration changes to 98%
99  X = Water in new thing = 98% of total
99X = 98/100 (100  X)
X=50 Actually, it is easier to concentrate on the thing that does not change. See approach 2 above. But whatever works for you!
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Re: Each of the cucumbers in 100 pounds of cucumbers is composed
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27 May 2014, 14:30
VeritasPrepKarishma wrote: shrive555 wrote: Each of the cucumbers in 100 pounds of cucumbers is composed of 99% water, by weight. After some of the water evaporates, the cucumbers are now 98% water by weight. What is the new weight of the cucumbers, in pounds?
A. 2 B. 50 C. 92 D. 96 E. 98 w1/w2 = (A2  Aavg)/(Aavg  A1) = (100  99)/(99  98) = 1/1 Hi Karishma, how did you get to the right side of "1/1"? Why did you state that both of the weights are the same?



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Re: Each of the cucumbers in 100 pounds of cucumbers is composed
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27 May 2014, 21:03
ronr34 wrote: VeritasPrepKarishma wrote: shrive555 wrote: Each of the cucumbers in 100 pounds of cucumbers is composed of 99% water, by weight. After some of the water evaporates, the cucumbers are now 98% water by weight. What is the new weight of the cucumbers, in pounds?
A. 2 B. 50 C. 92 D. 96 E. 98 w1/w2 = (A2  Aavg)/(Aavg  A1) = (100  99)/(99  98) = 1/1 Hi Karishma, how did you get to the right side of "1/1"? Why did you state that both of the weights are the same? The cucumbers left after some water has evaporated is 98% water. The evaporated water is 100% water. These two were mixed together in the original 100 pounds of cucumber. The original 100 pounds of cucumbers had 99% water. The formula of the scale method gives us: So w1/w2 = (A2  Aavg)/(Aavg  A1) A1  Water concentration of cucumber leftover = 98% A2  Water concentration of pure water = 100% w1  weight of cucumber leftover w2  weight of water w1/w2 = (100  99)/(99  98) = 1/1 So we can say that the weight of cucumber leftover and weight of water should be the same i.e. they both must be 50 pounds each. If you are unsure of this formula, check: http://www.veritasprep.com/blog/2011/03 ... averages/
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Re: Each of the cucumbers in 100 pounds of cucumbers is composed
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28 May 2014, 11:24
1 portion is non water  99 portions are water 1% 99% now after vaporization The 1 portion became 2% > we have to calculate 1 is 2% of what? x * 0.02= 1 > x= 100/2 > x=50 "the new whole. hope this one is simple enough!



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Re: Each of the cucumbers in 100 pounds of cucumbers is composed
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18 Jul 2014, 11:47
My 2 cents on mixtures and allegations.. Always deal with the quantity that does not change.. Mass content here does not change..hence play with this info Say Water is added to milk...Content of milk does not change..play with milk info..
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Re: Each of the cucumbers in 100 pounds of cucumbers is composed
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19 Jul 2014, 05:57
weight  99x (water), 1(other) ratio  98(water), 2(other) (99x)/1 = 98/2 x=50 i.e, 50 pounds of water evaporates Remaining is 50 pounds.
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Re: Each of the cucumbers in 100 pounds of cucumbers is composed
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10 Sep 2014, 14:16
shrive555 wrote: Each of the cucumbers in 100 pounds of cucumbers is composed of 99% water, by weight. After some of the water evaporates, the cucumbers are now 98% water by weight. What is the new weight of the cucumbers, in pounds?
A. 2 B. 50 C. 92 D. 96 E. 98 Sol: 100x/x =1/1 2x= 100 x=50



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Re: Each of the cucumbers in 100 pounds of cucumbers is composed
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23 Oct 2014, 08:25
Logically:
We should concentrate on nonwater component as not changing in number 1% of nonwater > 2% of nonwater doubling the concentration that can be only if we halve the total weight, so 100/2=50
Algebraic:
(99x/100x)*100=98 100=2x x=50, so 10050=50
B



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Re: Each of the cucumbers in 100 pounds of cucumbers is composed
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23 Oct 2014, 20:28
100 pounds of cucumbers have 99 pounds water and 1 pound solid.
Now 1 pound solid is 2% of the total cucumber weight.
So 98% of the cucumber which is water is 49 pounds. [ 2% > 1 what is 98% ? ......98% is 49]
Therefore the total cucumber weight is 50 pounds.



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Re: Each of the cucumbers in 100 pounds of cucumbers is composed
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27 Oct 2015, 06:50
shrive555 wrote: Each of the cucumbers in 100 pounds of cucumbers is composed of 99% water, by weight. After some of the water evaporates, the cucumbers are now 98% water by weight. What is the new weight of the cucumbers, in pounds?
A. 2 B. 50 C. 92 D. 96 E. 98 100 pound cucumber Haas 99% water I.e. 1% is the pulp in it On water evaporation, pulp remains same I.e. 1 pound pulp now should serve the purpose of 2% of total weight of leftover cucumber now because in new weight water is 98%. 1 pound = (2/100)*New weight I.e. New Weight = 50 Pound Answer : Option B
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Re: Each of the cucumbers in 100 pounds of cucumbers is composed
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21 Feb 2016, 01:04
weight * concentration = constant w1*c1 = w2*c2 100 * 1/100 = w2 * 2/100 w2 = 50 pounds.
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