Answer:
Step-by-step explanation:
1) First, we figure out the number of blue and green marbles (27 each)
2) Subtract the 6 blue and 3 green marbles. We now have 21 blue marbles and 24 green marbles.
3) Since we want to have more blue marbles while taking out the <em>minimum</em> number of green, we're going to take out green marbles out until there's one less than blue. Because there's 21 blue, we want 20 green. We've taken out 4/13 marbles so far.
4) Now, we're going to take 1 marble out of both the greens and blues until we have 17 blue and 16 green. We've now taken out 12/13 marbles. We can't make the 13th marble a blue one, otherwise we even them out, so we'll take another green. Now we have 17 blue and 15 green.
5) Count the number of greens you've taken out, and voila!
