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Robin mixes two liquids, one blue in colour and other red in
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27 Aug 2014, 00:24
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62% (02:43) correct 38% (03:10) wrong based on 202 sessions
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Robin mixes two liquids, one blue in colour and other red in colour in the ratio 3:1 and sells the mixture at the rate of $15 per litre, thereby making a 20% profit on his outlay. The blue liquid costs Robin $2 per litre lesser than the red liquid. How much does a litre of red liquid cost? A) $14 B) $13 C) $12 D) $11 E) $10 Source: 4Gmat Hi can someone share strategies and concepts on Ratios, Mixtures and Propotion
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Robin mixes two liquids, one blue in colour and other red in
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27 Aug 2014, 01:51
In mixture problem always try to make an equation, Questions says Robin sells the 1 litre of mixture for $15. The ratio given is 3:1 for Blue: Red. Let the multiplier for ratio be 1(take small and simple terms which is easy for calculation or multiple of 10. So we have 3 litre of blue liquid and 1 litre of red liquid. So total of 4 litre, Robin sells 4 litre of mixture for=4* 15= $60 We know that Blue cost $2 less than the red per litre. So B= R2 per litre. here we have 3 litre of blue= \(3(R2)\) Now since the question says he gets 20% profit. The equation will be, \([3(R2)+ R] + \frac{20}{100} [3(R2)+ R]= 60.\) On simplifying, \(1.2[3R6+R]= 60\) \(1.2(4R6)=60\) \(4R 6= 50\). \(4R= 56\) \(R= 56/4= 14\) The answer is A. Hope it helps Please see the below links for theory. 1. Work Problem Made Easy2. Mixture Problems Made Easy3. Word Problem Made Easy
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Robin mixes two liquids, one blue in colour and other red in
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28 Aug 2014, 04:26
Alternative Same approach as above but finding total cost first makes it easier:
Let x be the required cost per litre of red paint.
Take 4 litres of this mixture.
Sold at 60 with a profit of 1/5th of total cost. So, total cost will be 1/6th less than 60; total cost = 50.
3(x2) + 1(x) = 50
x = 14



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Robin mixes two liquids, one blue in colour and other red in
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14 Sep 2015, 00:33
B : R = 3 : 1 Cost of Red = x Cost of Blue= x2 What is the x?
Cost of mixture =(100/120)*15 => 12.5 dollars
0.75(x2)+0.25x=12.5 => x=14
A



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Re: Robin mixes two liquids, one blue in colour and other red in
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11 Jan 2016, 19:23
since we have 3/1 B/R, we can assume we have 4 liters in total. thus, 60$/total sold. 60=1.2x, where x is the cost, and 1.2 is the revenue. thus, x=60*10/12 = 50. now, 3B+R=50. B=R2. substitute: 3(R2)+R=50 3R6+R=50 4R=56 R=56/4 R=14. A.
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Re: Robin mixes two liquids, one blue in colour and other red in
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25 Nov 2017, 15:25
alphonsa wrote: Robin mixes two liquids, one blue in colour and other red in colour in the ratio 3:1 and sells the mixture at the rate of $15 per litre, thereby making a 20% profit on his outlay. The blue liquid costs Robin $2 per litre lesser than the red liquid. How much does a litre of red liquid cost?
A) $14 B) $13 C) $12 D) $11 E) $10 cost of liter of red liquid=c total cost=3(c2)+c=4c6 total revenue=4*15=$60 1.2*(4c6)=60 c=$14 A



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Re: Robin mixes two liquids, one blue in colour and other red in
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01 Mar 2019, 05:37
alphonsa wrote: Robin mixes two liquids, one blue in colour and other red in colour in the ratio 3:1 and sells the mixture at the rate of $15 per litre, thereby making a 20% profit on his outlay. The blue liquid costs Robin $2 per litre lesser than the red liquid. How much does a litre of red liquid cost? A) $14 B) $13 C) $12 D) $11 E) $10 Source: 4Gmat Hi can someone share strategies and concepts on Ratios, Mixtures and Propotion Selling price of the mix is $15 and profit is 20%. Cost Price * (6/5) = 15 Cost Price = 25/2 This is the average cost price of the mix when you put together blue liquid and red liquid. 25/2 = (Cb*3 + Cr*1) / (3 + 1) 3Cb + Cr = 50 Now we know that Cb (cost of blue liquid) is 2 less than Cr (cost of red liquid) 3(Cr  2) + Cr = 50 Cr = $14 Answer (A)
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Robin mixes two liquids, one blue in colour and other red in
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01 Mar 2019, 06:17
alphonsa wrote: Robin mixes two liquids, one blue in colour and other red in colour in the ratio 3:1 and sells the mixture at the rate of $15 per litre, thereby making a 20% profit on his outlay. The blue liquid costs Robin $2 per litre lesser than the red liquid. How much does a litre of red liquid cost?
A) $14 B) $13 C) $12 D) $11 E) $10 At a rate of $15 per liter, the selling price for a 4liter mixture composed of 3 liters of blue and 1 liter of red = 4*15 = 60. 20% profit = 120% of the cost = 6/5 of the cost. Since the selling price is 6/5 of the cost, the cost is 5/6 of the selling price: Cost of 3 liters of blue and 1 liter of red = 5/6 * 60 = 50 We can PLUG IN THE ANSWERS, which represent the cost for each liter of red. The prompt indicates that each liter of blue costs $2 less than each liter of red. When the correct answer is plugged in, 3 liters of blue and 1 liter of red will cost $50. B: $13, implying that the cost of each blue liter = 132 = 11 Cost of 3 liters of blue and 1 liter of red = (3*11) + 13 = 46 Since the cost is too low, a greater answer choice is needed.
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Re: Robin mixes two liquids, one blue in colour and other red in
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02 Mar 2019, 04:38
GMATGuruNY wrote: alphonsa wrote: Robin mixes two liquids, one blue in colour and other red in colour in the ratio 3:1 and sells the mixture at the rate of $15 per litre, thereby making a 20% profit on his outlay. The blue liquid costs Robin $2 per litre lesser than the red liquid. How much does a litre of red liquid cost?
A) $14 B) $13 C) $12 D) $11 E) $10 At a rate of $15 per liter, the selling price for a 4liter mixture composed of 3 liters of blue and 1 liter of red = 4*15 = 60. 20% profit = 120% of the cost = 6/5 of the cost. Since the selling price is 6/5 of the cost, the cost is 5/6 of the selling price: Cost of 3 liters of blue and 1 liter of red = 5/6 * 60 = 50 We can PLUG IN THE ANSWERS, which represent the cost for each liter of red. The prompt indicates that each liter of blue costs $2 less than each liter of red. When the correct answer is plugged in, 3 liters of blue and 1 liter of red will cost $50. B: $13, implying that the cost of each blue liter = 132 = 11 Cost of 3 liters of blue and 1 liter of red = (3*11) + 13 = 46 Since the cost is too low, a greater answer choice is needed. Dear GMATGuruNY1 Is not the ratio of costs same as ration of amounts of both liquids i.e. 3/1? 2 I know your solution is the better, but Can you use alligation? Thanks



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Re: Robin mixes two liquids, one blue in colour and other red in
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03 Mar 2019, 05:31
Quote: Dear GMATGuruNY1 Is not the ratio of costs same as ration of amounts of both liquids i.e. 3/1? The cost ratio and the volume ratio can be quite different. While the red liquid constitutes 1/4 of the total volume, it does not necessarily constitute 1/4 of the total cost. Consider the following case: Cost of the blue liquid = $1 per liter. Cost of the red liquid = $1000 per liter. Cost of 4 liters of a 3:1 solution = (3*1) + 1000 = $1003. In this case, much more than 1/4 of the total cost  in fact, almost 100% of the total cost  is attributable to the red liquid. Quote: 2 I know your solution is the better, but Can you use alligation?
Thanks To apply alligation here would likely be more confusing than helpful.
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Re: Robin mixes two liquids, one blue in colour and other red in
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