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sayan640
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How many liters of a solution that is 15% salt must be added to 5 litre of a solution that is 8 % salt so that the resulting solution is 10 %salt
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It’s 2litre
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krida
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Can you please share solution
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form n alligtion diagram

15 ------------10 ---------8

2--------10----------------5

2 is the weight for 15% solution
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krida
How many liters of a solution that is 15% salt must be added to 5 litre of a solution that is 8 % salt so that the resulting solution is 10 %salt
You can do like this also-
0.15x + 0.4 = 0.10 ( x+ 5 ) , solve for x , you’ll get 2
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krida
How many liters of a solution that is 15% salt must be added to 5 litre of a solution that is 8 % salt so that the resulting solution is 10 %salt
­
You can check detailed discussion of this question here: https://gmatclub.com/forum/how-many-liters-of-a-solution-that-is-15-percent-salt-must-be-added-to-340799.html 

Hope it helps.
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Please how to solve this
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Where is this question from?
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Edoua
Please how to solve this
IMO D

My answer , please lwt me know if theres anything wrong

Usual weekend revenue = 20*40= 800$
If for every 2$ price decrease, 20 more are sold
Weekend revenue= f(x) = (20-2x)(40+20x)=800+320x+40r^2
F’(x)= 320-80x
320-80x= 0 for x=4 then inflection point of fx is at x=4 which is max in this case
F(4) = 1440
1440-800=640 which is answer D


Let know please if there’s anything wrong
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Here’s an easy way.
Intially , 20 X 40 = 800. After that price starts decreasing and quantity starts increasing .
18 X 60 = 1080
16 X 80 = 1280
14 X 100= 1400
12 X 120 = 1440
10 X 140 = 1400. Here it starts decreasing .
Maximum revenue can be increased by 1440-800 = 640.
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SATYAM7777
Here’s an easy way. Intially , 20 X 40 = 800. After that price starts decreasing and quantity starts increasing . 18 X 60 = 1080 16 X 80 = 1280 14 X 100= 1400 12 X 120 = 1440 10 X 140 = 1400. Here it starts decreasing . Maximum revenue can be increased by 1440-800 = 640.
Thank you.. I understand clearly now
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IMO D

we can start by calculating the maximum which is -(-(1/25)^(-1/3)) as it it the only positive number.
-(-(1/25)^(-1/3)) = cubic root (25)

we can also deduce that -(1/5)^(-2/3) is the minimum as it has the largest numerator =5^2 among all the other negative numbers.
-(1/5)^(-2/3) = (5^2)^(-1/3) = - cubic root (25)

Range = cubic root (25) - - cubic root (25)= 2 * cubic root (25)
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One more fresh and tough problem from GMAT Club Tests:

https://gmatclub.com/forum/the-value-of ... 26891.html

Try it!
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Tags for both of the questions say they’re 600-650
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Nullbyte
Tags for both of the questions say they’re 600-650
­When I post a question, I typically label it with a medium difficulty tag. However, after users attempt it using our timer, the difficulty tag will be automatically adjusted based on the timer results.
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Bunuel
When I post a question, I typically label it with a medium difficulty tag. However, after users attempt it using our timer, the difficulty tag will be automatically adjusted based on the timer results.
Oh cool

The % of people of got it wrong doesn’t affect it?

Only the timing does?
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