[helter skelter]

I guess this is the forum to post this in. I was about to post in poker theory when I saw this forum.

I am trying to determine the probability of an ATC limper flopping a flush draw, given that I have one of his suit

I take out my 2 cards and opponents 2 cards from the 52 card deck to get 48

There are 10 flush cards left in the deck, he needs to flop 2 out of three on the flop

If I use the poker odds calculator, plugging in 10,2,3,48, I get 0.098866790 probability

If I work backwards after the flop:

I use binomial calculator plugging in 47 (subtracting my cards and flop), 2, I get 1081 possible hands he could have started with

then I go to a hand chart and count the possible hands he could have with 2 flush cards and they total 45

so 45/1081 = 0.041628122

I was expecting these 2 numbers to be the same, so what am I missing here?