I had problems like these how I figure them out is
I add all the marble i have So 3 green marbles + 2 yellow marbles + 6 Blue marbles + 9 red marbles = 20 marble altogether
The probability of picking a blue marble out the bag is \(\frac{6}{20}\)
Because there is 20 marble and 20 of those marbles are blue
Just like the probability of picking a red marble is \(\frac{9}{20}\)
The probability of picking a green marble is \(\frac{3}{20}\)
And the probability of picking a yellow marble is \(\frac{2}{20}\)
So your answer for the probability of picking a blue marble from the bag is \(\frac{6}{20}\)
