A bag contains four yellow marbles, six red marbles, five blue marbles, six white marbles, and four black marbles. What is the theoretical probability of pulling a white marble from the bag?

1. 4/25

2. 6/19

3. 4/21

4. 6/25

Hello! To find the probability, first we add up all the marbles together since each one has a chance of being chosen.

4 + 6 + 5 + 6 + 4 = 25

So, we can get rid of 2. and 3. since both do not have "25". Why can't "19" and "21" be possible? Because if all the marbles are within this bag, it's impossible to say each and every marble doesn't have the same equal chance of being chosen. It's only when we're talking about a certain group of objects being chosen to we dive deeper into the probability and percentages.

Next we try to find what is the probability of choosing a white marble; so we look for how many white marbles are within the 25 to find that there are 6. This means answer 4. is correct since it says 6/25, showing the amount of what object you're aiming to choose within the other 19 objects which together equal 25.

4 yellow, 6 red, 5 blue, 6 white, 4 black ... total = 25

P (white marble) = favorable outcomes / total outcomes = 6/25 <==