when a single die is rolled, find the probability of each event...

Question

When a single die is rolled, find the probability of each event.

(a) the number 2 is rolled

(b) a number other than 2 is rolled

(c) the number 7 is rolled

(d) a number less than 7 is rolled

Answer 1

Probability is the number of events-of-interest divided by the total number of possible events. A die has 6 sides so there are 6 total events that can occur each time it is rolled. For each die, there is only, for example, one number 2. So 1 divided by 6 equals the probability of rolling a number 2. 

For part D, don't get tripped up that it asks for the probability of a group of numbers... so if there is a problem that says, "Find the probability of rolling an even number on a die," well there are only 3 even numbers (2,4,6) on a die. Or, "find the probability of rolling a number less than 4 on a die" so only the numbers 1, 2 and 3 are considered events-of-interest.

 

Plug it in and solve!