Jim rolls a fair dice 36 times. How many times would Jim expect to roll a three?

Answer 1

Annabel,

this problem is an example of binomial probability, so you can apply the expected value formula which can only be used for binomial probabilities.

The probability of rolling a 3: p=1/6, n=36

E(x)=np = (1/6)*36 = 6.

Jim will likely roll the number 3 6 times out of 36 repeats.