WARNING: I am not toooooo good at this probability stuff....but here is my answer
you draw one card....it is a ' given ' it WILL be ONE of the suits
probability: 1
Now you have 51 cards left, 39 of which are a 'different' suit. SO you have a 39/51 chance of getting a different suit.
1 x 39/51
Now you have 50 cards left.... only 26 are a different suit than the first two drawn, so you have a 26/50 chance of a different suit
1 x 39/ 51 x 26/50 = .3976 or 39.76% chance of getting THREE different suits (using a standard poker deck of 52)
Anyone else get the same answer???