Emilia is using a spinner that has outcomes and probabilities as shown in the table.
Outcome | Blue | Yellow | Green | Red | Purple |
Probability | 0.2 | 0.1 | 0.4 |
The spinner has an equal chance of landing on blue or red.
Complete the probability table.
The probabilities of all the outcomes should add up to 1.
1 - 0.2 - 0.1 - 0.4 = 0.3
The probability that it lands on blue or red is 0.3.
As the probabilities of blue and red are equal you can halve this to get each probability.
0.3 ÷ 2 = 0.15
Now complete the table.
Outcome | Blue | Yellow | Green | Red | Purple |
Probability | 0.15 | 0.2 | 0.1 | 0.15 | 0.4 |
Find the probability that the spinner lands on green or purple.
As the spinner can not land on green and purple at the same time they are mutually exclusive.
This means you can add their probabilities together.
0.1 + 0.4 = 0.5
P(Green or Purple) = 0.5
Find the probability that the spinner does not land on yellow.
The probability of not landing on yellow is equal to 1 minus the probability of landing on yellow.
1 - 0.2 = 0.8
P(Not Yellow) = 0.8
Some harder questions may not say "by drawing a grid" so you have to decide to do it on your own.
Two fair six-sided dice are rolled.