Rewind back to class

I want to talk about another activity we did in class last week (the day we used face cards for probability). Not only did we use the cards, but we also used Pom Poms to make tree diagrams. Pom Poms are like little fluffy balls- almost like a cotton ball. We used white and black ones. Man was that tricky! I am still a little confused with it, but I think I got it now?! Here is an example we had...

A box contains three white balls and two colored balls. A ball is drawn at random from the box and not replaced. Then a second ball is drawn from the box. Draw a tree diagram for this experiment and all possible outcomes. Find the probability that the two balls are different colors.

So above the problem is the diagram I drew. On the first draw you either get a black or white ball. Then on the second draw, it is the same outcome since you replaced the balls so you add that outcome to the first one (look at picture).  The cool thing I learned about tree-diagrams is that you can check your work! On each "<" sign, the probability of drawing each object on either side of it must equal one. For example, if you look at the first "<", the probability to get a white ball (3/5) and the probability to get a black ball (2/5) add to one when put together so you know you did it right! Now that we drew the tree-diagram, we have to find the probability that the two balls are different colors. On the side of the diagram, I drew all of the outcomes. So we find the outcomes that have one of each color. Then you have to multiply the probability of getting the first color to the second color to find the probability of getting both (follow the lines on the diagram to know what numbers to multiply). Then you add those two probabilities together! See it sounds really tricky right?! So HERE is a link in case you need more practice, like me! ;)