the bag has 12 blue balls
the probability of a red ball drawn is 6. if the probability of a blue ball being drawn is twice the red ball, then multiply the red ball probability (6) by 2.
6 x 2 = 12
to check the answer:
when we calculate the probability of each ball, 6 + 12 = 18, which is the total number of balls.
red ball probability = 6/18 = 33.33%
blue ball probability = 12/18 = 66.66%
therefore, the answer of 12 blue balls in the bag is correct