A cube has six sides that are numbered 1 to 6. The sides numbered 1, 2, and 5 are green, and the sides numbered 3, 4, and 6 are red. What is the probability of rolling the cube and getting a green or even number?

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Answer 1 · 2018-05-17T17:50:22

See explanation.

In the task we have the following events:

#G# - choosing a green side

#E# - choosing a side with an even number

#GnnE# - choosing a side which is green and has an even number

#GuuE# - - choosing a side which is green or has an even number

The probabiliyies are:

#P(G)=3/6=1/2# (there are #3# green sides)

#P(E)=3/6=1/2# (there are #3# sides with an even number)

#P(GnnE)=1/6# (there is one green side with an even number: #2#)

Now to calculate the probability of the sum of events we use the formula:

#P(GuuE)=P(G)+P(E)-P(EnnG)#

If we do the calculation we get:

#P(GuuE)=1/2+1/2-1/6=1-1/6=5/6#