You roll a die 5 times. What is the probability that:

Question

a. The number 1 is rolled each time?

b. An odd number is rolled each time?

Answer 1

a. consecutive rolls mean multiplication of each individual probability.  there is 1 one on a die, and 6 total outcomes which means a 1/6 probability each time(no need to subtract 1, you can't take the #1 off of a die.)

 

next multiply 1/6 times 1/6 times 1/6 times....a total of 5 times.

 

b. how many odd numbers are there on a die?  1,2,3,4,5,6 possibilities, so 1,3,5 are odd.  3/6 probability.

consecutive rolls mean multiplication.  3/6 times 3/6 times.... a total of 5 times.  reduce you answer.

Answer 2

a. (1/6)⁶, since every roll does not depend on the previous outcome, and the probability of rolling 1 once is 1/6.

 

b. You can roll odd number by 3 ways: roll 1, 3, or 5. So the probability to roll odd number once is 1/2, then rolling it 6 times is (1/2)⁶=1/64=0.015625.