Answer:
First, we need to find the total volume of the mixture by adding the volume of solution A and solution B: 750 mL + 780 mL = 1530 mL.
We can then divide the total volume of the mixture by the number of beakers to find out how much should be poured into each beaker: 1530 mL / 12 beakers = 127.5 mL/beaker.
Therefore, each beaker should be filled with 127.5 mL of the mixture.
which is B