Equal volumes of water were poured into 3 empty flasks

Equal volume is poured into all three jars.

Half of that volume from each of two smallest jars is taken, on addition that will be equal to the original volume of water poured in the biggest jar. So the volume in biggest jar gets doubled.

Initial volume of biggest jar was 1/12 after doubling it will be 1/6

So option A.

We can assume that 2 ounces of water are poured into each of the flasks. Thus, the full capacities of the flasks are 12 oz, 16 oz, and 24 oz, respectively.
If half of the water from each of the two smallest flasks is then poured into the largest (24 oz) flask, then the largest flask will have 2 + 1 + 1 = 4 ounces of water and thus it will be
4/24 = 1/6 full.

Alternate Solution:

There were equal amounts of water in all the flasks and since half the water from the two smaller flasks is poured into the largest flask, the amount of the water in the largest flask will double. Since the largest flask is the one that was 1/12 full (which is because the same amount of water filled the least fraction of the flask); after the water is doubled, it will be 2 x 1/12 = 1/6 full.

Answer: A

Lets substitute numbers for these kind of questions

Critical information:
Equal number of water is filled in all flasks. So lets consider 2 liters to be that amount.

Flask A: 2 liters is 1/6 = capacity is 12 liters
Flask B: 2 liters is 1/8 = capacity is 16 liters
Flask C: 2 liters is 1/12 = Capacity is 24 liters

Now take half of Flask A and B and add it to Flask C. Add 1 liter each from Flask A and B to Flask C.

Flask C how have: 2 Liters(initial amount)+1+1 = 4 liters

4 liters is 1/6 of total capacity.

Ans: A

A


X/6 = Y/8 = Z/12

two smallest jars - x,y

x=z/2 , y=2z/3

x/2 + y/2 = z/12

Z/12 + Z/12 = Z/6

Before doing any calculation one should note that logically 1/12 jar is greater than 1/8, and 1/8 jar is greater than 1/6. Let's take 24 as an equal volume for the three jars. The 1/6 jar will have 144 space in total (24*6), the 1/8 jar will have 192 space and 1/12 jar will have 288 space in total.
Now when we fill half of the water from the smallest jars to the largest one, we combine 12+12+24=48. We can answer the question from now on, what fraction of the largest jar can be filled with water? -- it is 48/288, which is 1/6.