Question

Luke starts of two silver and eight red balloons he's going to choose two balloons at random to inflate copy and complete the tree diagram to show all the possible outcomes what is the probability that Luke chooses a silver balloon and then a red balloon give your answer as a fraction in its simplest form

Answer 1

The probability of selecting first a silver balloon and then a red one is:

p = 8/45

How to find the probability?

We know that here we have 2 silver balloons and 8 red ballons, and Luke selects two, so the possible outcomes are:

• red red
• red silver
• silver red
• silver silver

We want to find the probability of first selecting a silver one and then a red one.

There are 10 balloons in total, and 2 are silver, then the probability of selecting a silver one is

P = 2/10

Now there are 9 ballons, 1 silver and 8 red ones (because we already selected a silver one)

The probability of getting a red one is:

Q = 8/9

The probability that both things happen in sequence is equal to the product between the individual probabilities:

prob = (2/10)*(8/9) = 16/90 = 8/45