I'm Kate Walace It's a 9th grade question and I am a student.

The question is on Probability:

If I have a spinner and then spinner has the numbers 1,2,3,4 on it and it is spun 3 times, what is the probability that the spinner will stop on 4,3,and 1 ? In that order?

Can you help?

If so thank you. Kate



Hi Kate,

Recall that the probability of an outcome of an experiment is:

For the spinner with numbers 1, 2, 3 and 4 there are 4 possible outcomes. A successful outcome such as in your question would be spinning a certain number. For example there would be one successful outcome for spinning a 1, that would be landing on the 1.

So for your question, the probability of spinning a 4 on the first spin is 1/4, of spinning a 3 on the second spin is 1/4 and of spinning a 1 on the third spin is 1/4. Since you need all three of these to happen, that is, you need:

4 on the 1st spin AND 3 on the 2nd spin AND 1 on the 3rd spin

The answer is found by multiplying the three probabilities together to get 1/64.

If we list the entire sample space for the three spins we would see that only one of the 64 possible outcomes╩corresponds to 4, 3 and 1 in that order.

Hope this helps,

Leeanne

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