jaspreetsra wrote:Solution Y is 30 percent liquid X and 70 percent water. If 2 kilograms of water evaporate from 8 kilograms of solutions Y and 2 kilograms of solution Y are added to the remaining 6 kilograms of liquid, what percent of this new liquid solution is liquid X?
a 30%
b 33 1/3%
c 37 1/2%
d 40%
e 50%
Didn't get it.
2 kilograms of water -- 1/4 of the original 8 liters of mixture -- evaporates and is replaced by Solution Y.
The correct answer will be obtained as long as 1/4 of the original volume evaporates and is replaced by Solution Y.
Thus, we can make the math easier by rephrasing the problem as follows:
Solution Y is 30 percent liquid X and 70 percent water. If 25 liters of water evaporates from 100 liters of Solution Y, and 25 liters of Solution Y is added to the remaining 75 liters of liquid, what percent of this new liquid solution is liquid X?
a 30%
b 33 1/3%
c 37 1/2%
d 40%
e 50%
Original mixture:
Total volume = 100 liters.
Amount of liquid X = 30% of 100 = 30 liters.
Amount of water = 70% of 100 = 70 liters.
New mixture:
Here, 25 liters of water is replaced by 25 liters of Solution Y.
Amount of liquid X remaining from the original mixture = 30 liters.
Amount of liquid X in the 25 liters of added Solution Y = 30% of 25 = 7.5 liters.
Resulting percentage:
(total amount of liquid X)/(total volume) = (30 + 7.5)/100 = 37.5%.
The correct answer is
C.
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