In a chemistry lab, Tank A and Tank B are both filled to capacity with

Question

In a chemistry lab, Tank A and Tank B are both filled to capacity with different solutions. During the day, 12 percent of the volume of liquid in Tank A was used for an experiment, and 68 percent of the volume of liquid in Tank B was used for an experiment. Together, these amounts equal 26 percent of the combined volume of liquid in Tank A and Tank B.

Select for Tank A and Tank B, the capacities, in cubic meters, of Tank A and Tank B, that are jointly consistent with the information. Make only two selections, one in each column.

Select for  Tank A  and  Tank B , the capacities, in cubic meters, of Tank A and Tank B, that are jointly consistent with the information. Make only two selections, one in each column.

Bunuel · Accepted Answer

https://gmatclub.com/forum/download/file.php?id=85929 Use the weighted-average (alligation) idea. The combined 26% used is a weighted average of 12% (Tank A) and 68% (Tank B). Measure each rate’s distance from 26%: For A, 26 - 12 = 14; For B, 68 - 26 = 42. For a weighted average to land at 26%, the weights are inversely proportional to these distances, so A:B = 42:14 = 3:1. That means Tank A must have three times the capacity of Tank B. From the table, the only pair with A three times B is A = 51 and B = 17 . I29-174 GMAT-Club-Forum-gl89y1eq.png

Dereno · Answer

Let the volumes of Tank A and Tank B be A and B respectively.

The consumption per tank are as follows:

12% A and 68% B.

Moreover it’s given that the total consumption = 26%*(A+B)

12% A + 68% B = 26% * (A+B)

Solving we get,

12 A + 68 B = 26 A + 26 B

14 A = 42 B

3B = A

When , B = 17, A = 51.

paragw · Answer

Simply apply alligation: https://gmatclub.com/forum/download/file.php?id=85945 This will give us the ratio of volume: A:B=3:1 Only option satisfies is A=51 & B=17 GMAT-Club-Forum-edxx9oqt.png

Vaishbab · Answer

12% of A's volume + 68% of B's volume gives 26% of the combined volume of A & B

That means 0.12A + 0.68B = 0.26(A+B)

Solving the equation, we get 0.42B = 0.14A

Which means 3B = A

A is 3 times that of B. The only options that satisfy this are A = 51 and B = 17.

AbhishekP220108 · Answer

Let tank A have a capacity of X, and tank B have a capacity of Y.

taken from Tank A is 12% of X and from Tank B is 68% of Y.

together 12%X and 68%Y makes 26%(X+Y)

so we have 2 method to solve this:

1 Alligation method

X Y
12 68

26(X+Y=R)

42(Y-R) 14(R-X)

X/Y=42/14=3/1 and only option in table is 51/17

2 algebraic equation

0.12x+0.68y=0.26(x+y)

solving this we will get the same.

Hope it helps

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