PS 1000-Section 3 #18

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PS 1000-Section 3 #18

by lavanya_25 » Mon May 07, 2007 11:06 am
Hi

One more from the PS 1000 series....

Solution Y is 30 percent liquid X and 70 percent water. If 2 kilograms of water evaporate from 8 kilograms of solution Y and 2 kilograms of solution Y are added to the remaining 6 kilograms of liquid, what percent of this new solution is liquid X?
(A) 30%
(B) 33 1/3 %
(C) 37 1/2 %
(D) 40%
(E) 50%

I kind of kept getting 30% but the answer is C. So could someone explain this to me.

Lavanya
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Re: PS 1000-Section 3 #18

by jayhawk2001 » Mon May 07, 2007 7:37 pm
lavanya_25 wrote:Hi

One more from the PS 1000 series....

Solution Y is 30 percent liquid X and 70 percent water. If 2 kilograms of water evaporate from 8 kilograms of solution Y and 2 kilograms of solution Y are added to the remaining 6 kilograms of liquid, what percent of this new solution is liquid X?
Start off with 8 kg of Y = 2.4 (of x) + 5.6 (of w)
2 kg of water evap = 2.4 (of x) + 3.6 (of w)
Add 2 kg of y: 2.4+0.6 (of x) + 3.6+1.4 (of w)
= 3 of x + 5 of w

x/(x+w) = 3/8*100 = 37.5%

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by Cybermusings » Tue May 08, 2007 1:59 am
Solution Y is 30 percent liquid X and 70 percent water. If 2 kilograms of water evaporate from 8 kilograms of solution Y and 2 kilograms of solution Y are added to the remaining 6 kilograms of liquid, what percent of this new solution is liquid X?
(A) 30%
(B) 33 1/3 %
(C) 37 1/2 %
(D) 40%
(E) 50%

.3x ---- liquid
.7x ---- water

8 kg solution has 2.4 kg liquid and 5.6 kg water
If 2 kg water evaporates we have 3.6 kg water left
2 kg of solution will have .6 kg liquid and 1.4 kg water

Liquid X in the solution = 2.4 + .6 = 3kg
Total solution = 2.4 + .6 + 1.4 + 3.6 = 8 kg
So % = 3/8 * 100 = 37.5

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by lavanya_25 » Tue May 08, 2007 6:57 am
Thank you for helping me out with this problem.

Lavanya