In order for 4 red marbles to be one-third of a group and 3 blue marbles to make up one-fourth of the same group the number has to equal 12.
5 marbles
The first could be white, the second could also be white, but for the third there are no white left so the third would have to be black. The first or second could be black, but to guarantee at least one black you need to remove 3 marbles.
I think the trading is the other way around and then the answer is 18 marbles in all.
18 of them.
minus one red marble plus one blue marble
The second and third marbles depend upon the first, so they are dependent. Even if they are all being drawn together, because there is no replacement, each removal affects the original group of marbles.
15
The third Olympic medal color is bronse.
You would need to take out at least 5 marbles to ensure you have 3 of the same color. This is because in the worst-case scenario, you could end up with 2 marbles of each color after drawing 4 marbles (2 white, 2 black) and adding 1 more marble guarantees that you will have at least 3 of one color.
My third favorite color is purple what's yours? --------------------------------------------------------- My favorite color is red, my second favorite color is white, and I don't have a third favorite color! Hehe!
I think red is the third most popular color.