Question:Helena
has a set of number cards numbered 1 thru 10. If Helena randomly draws
two cards from the deck, what is the probability that she will draw an
odd number and then a two?

The probability of taking an odd card from initial deck is 5/10 (or 1/2), then the probability to take a 2 from the remaining deck is 1/9. Either way we get 5/10 * 1/9 = 5*90 or 1/18 which is the same number.