169k views
16 votes
What is the probability of rolling a 3 on a six-sided cube AND rolling a 6 on a six-sided cube?

ob

User Eraklon
by
7.4k points

2 Answers

5 votes

Answer:

16.7%

Explanation:

There are 6 sides and one three on the cube so rolling a three would be 1/6. To roll a 6 on a 6 sized dice would be the same there’s 6 sides and one 6 so it would be 1/6

User Floran Gmehlin
by
8.5k points
7 votes

Answer:

The probability of not rolling a 5 AND not spinning a 5 is (5/6)*(4/5)=20/30

Explanation:

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.

User Euan Smith
by
8.7k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories