Odd numbers are of the from a(n)=a+d(n-1) where a=1 and d=2 so
a(n)=1+2(n-1)=2n-1 and we need the number of odds in the range 1 to 38
2n-1≤38
2n≤39
n≤19.5, so there are 19 odd numbers in [1,38]
And since Julie bet on two even numbers as well, the probability of getting an odd number or the two evens she picked is:
(19+2)/38
21/38
Plug in the values of xy/z
(-2*-3)/4
=6/4
=3/2
