Question 594508
We can either roll an odd followed by an even, or an even followed by an odd. Rolling an odd or an even occurs with probability 1/2, so


P(one odd and one even) = (1/2)(1/2) + (1/2)(1/2) = 1/2.


Or, we can find the probability of getting two odds or two evens, and subtract the result from 1.