Question

A single die is rolled one time. Determine the probability of rolling a number greater than 3 or less than 5?

Answer 1

isnt that guaranteed to happen when a single die is rolled?

Answer 2

I don't know?

Answer 3

you can either roll a 1,2,3,4,5, or 6.

Answer 4

It will always be greater than 3 OR less than 5.

Answer 5

So whats the probability of an event that is 100% to occur?

Answer 6

Let's examine the outcomes: {1, 2, 3, 4, 5, 6}
We assume they are equally likely.
Which outcomes are greater than three? That's right, 4, 5, 6
Which outcomes are smaller than five? 1, 2, 3, 4

What numbers *don't* fulfill these criteria?
That's right - no numbers. So the probability is 6/6, i.e. 100%

what I assume you mean, is the probability for getting a number larger than 3 AND less than 5? What numbers fulfill these criteria? That's right only 4. So we have one outcome out of 6 that fulfills this, meaning the odds are 1/6, i.e. 16.667%

Answer 7

@SSODELTA You can't assume that, as perhaps the question is testing what it set out to test. To determine if the student understand that a guarantted even has a probability of 1.

Answer 8

@Easyaspi314
To me, it's a mundane question, though, but maybe that's just me.

Answer 9

The equation that the text book gives me is P(A or B)=P(A) + P(B)-P (A and B).

Answer 10

That's correct, and is used in this case as events A and B are not mutually exclusive. So use the formula.

Answer 11

This is what I have P(greater than 3) + P( less than 5) - P(1/6)
P(3/6)+ P(4/6) - P(1/6)
7/6-1/6=1
Is this correct?

Answer 12

yes

Answer 13

Okay Thank You so much!

Answer 14

welcome.