By weight, liquid A makes up 8 percent of solution R and 18 percent of

Question

By weight, liquid A makes up 8 percent of solution R and 18 percent of solution S. If 3 grams of solution R are mixed with 7 grams of solution S, then liquid A accounts for what percent of the weight of the resulting solution?

A. 10%
B. 13%
C. 15%
D. 19%
E. 26%

A. 10%
B. 13%
C. 15%
D. 19%
E. 26%

gracie · Answer

5 of liquid A in final solution

let x=% of liquid A in final solution
.08*3+.18*7=10x
x=.15=15%
C

AkshdeepS · Answer

Weighted Avg. method :

Let us say liquid A accounts for x% weight of the final solution

\frac{3}{7} = \frac{18 - x}{x - 8}

10x = 150

x = 15%

(C)

GMATbuster92 · Answer

total solution = 3+7 =10
total weight of A = 3*8% + 7* 18% = 1.5
% of solution A = 1.5/10 *100 = 15%

quaes · Answer

\frac{(3×8 + 7×18)}{(3 + 7)}  =  \frac{150}{10}  = 15 (C)

Seryozha · Answer

Since the question asks for the weight of the Liquid A, we should find the availability of Liquid A in the mixture. Logically the percentage does not change even when the gram raises. 
8% of Liquid A in the 3 gram of R = 0.08*3=0.24
18% of Liquid A in the 7 gram of S = 0.18*7=1.62
Now we should turn this into part/total form.
1.5/10*100=15%

ScottTargetTestPrep · Answer

Solution:

/ (3 + 7)

=   / 10

= 1.5/10

= 15/100

= 15%

Answer: C

Shaw9 · Answer

Liq. A - 8% of 3grams (Sol. R)
Liq. A - 18% of 7 grams (Sol. S)

Total weight of both Solutions: 3+7= 10

A conc.= (8*3)+(18*7)/ (3+7) = 15

Aswatha · Answer

Liquid = x

8% of A and 18% of B
8/100 * 3gram + 18/100 * 7gram = 0.08*3+0.18*7 = 0.24+1.26 = 1.50grams

1.50 grams/total weight (7+3) = 1.50/10*100 = 15%

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By weight, liquid A makes up 8 percent of solution R and 18 percent of

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