Cameron rolls a number cube and spins a 5-part spinner, labeled 1, 2, 3, 4, and 5. What is the probability that he rolls 5 or spins a 5? Explain your answer

Cameron rolls a number cube and spins a 5-part spinner, labeled 1, 2, 3, 4, and 5. What is the probability that he rolls 5 or spins a 5? Explain your answer

Tutors, sign in to answer this question.

These are independent events.

The probability of rolling a 5 is 1/6.

The probability of spinning a 5 is 1/5.

The probability of rolling a 5 or spinning a 5 is 1/5+1/6=11/30 but you have to subtract 1/30 because you can roll a 5 and spin a 5 at the same time. Therefore 11/30-1/30=10/30=1/3.

There are 30 outcomes. Roll first then spin to get the following outcomes:

11,12,13,14,15,21,22,23,24,25,31,32,33,34,35,41,42,43,44,45,51,52,53,54,55,61,62,63,64,65

You want to roll a 5 OR spin a 5. How many combinations have a 5 ? 10 combinations have a 5.

(you don't count 55 twice) There are 10 combinations with a 5 out of a possible 30 combinations.

Another way of looking at the problem is the following:What is the probability of NOT rolling a 5 AND NOT spinning a 5 ?

The probability of not rolling a 5 AND not spinning a 5 is (5/6)*(4/5)=20/30. Therefore the probability of rolling a 5 or spinning a 5 is 1-20/30=10/30.

There are six outcomes for the cube and five outcomes for the spinner, for a total of 6*5=30 outcomes (1-1, 1-2,..., 6-5).

In six of those outcomes the spinner spins a 5 (1-5, 2-5,...,6-5), and in five outcomes the cube rolls a 5 (5-1, 5-2, ..., 5-5). There is exactly one outcome where the spinner spins 5 AND the cube rolls 5 (5-5), which should only be counted once, so there are 6+5-1=10 outcomes where the spinner spins 5 OR the cube rolls 5.

Therefore, the probability that he rolls 5 or spins a 5 is 10/30=1/3.

Hi Chris;

The cube must have six sides, six potential results. I assume each side is denoted the numbers 1-6 and that each denotation occurs once.

The spinner has five parts, five potential results. You have informed me that each part is denoted the numbers 1-5 and that each denotation occurs once.

6 sides + 5 parts=11 parts

The number 5 appears twice.

2/11

Already have an account? Log in

By signing up, I agree to Wyzant’s terms of use and privacy policy.

Or

To present the tutors that are the best fit for you, we’ll need your ZIP code.

Your Facebook email address is associated with a Wyzant tutor account. Please use a different email address to create a new student account.

Good news! It looks like you already have an account registered with the email address **you provided**.

It looks like this is your first time here. Welcome!

To present the tutors that are the best fit for you, we’ll need your ZIP code.

Please try again, our system had a problem processing your request.