If the probability of an event E is p, then (by definition) the odds of E is p/(1-p). In this case, the odds of being dealt two pairs in a five care poker hand is 0.0475/(1-0.0475) = 0.0475/0.9525 ~ 0.0499. This may seems a little weird since the odds of E ~ p: it's because p is so small. For more See this