Question

What is the probability of rolling a six-sided number cube and getting an odd number or a number less than 4?

Answer 1

`Pr(Odd\ or\ <4) = (2)/(3)`

Explanation:

Given

`S = \{1,2,3,4,5,6\}` --- roll of a die

`n(S) = 6` ---- the sample size

`Odd = \{1,3,5\}`

`<4 = \{1,2,3\}`

Required

`Pr(Odd\ or\ <4)`

First, list out the event of odd or <4

`Odd\ or\ <4 = \{1,2,3,5\}`

So, the probability is:

`Pr(Odd\ or\ <4) = (n(Odd\ or\ <4))/(n(S))`

`Pr(Odd\ or\ <4) = (4)/(6)`

Simplify

`Pr(Odd\ or\ <4) = (2)/(3)`