This is a basic probability calculation - we can ignore your hole cards
Take your first example - flop of 235
Since 235 / 532 / 325 etc are equivalent to us, we can ignore the sequence and the suit
For the 1st card on the flop there are 12 cards of 50 that fit our criteria
for the 2nd card there are 8 of 49
for the 3rd card there are 4 of 48
So the probability of a flop with 235 or a variation of that is
(12/50) * ( 8/49) * (4/48) = 0.0032 = 0.32%
Put another way about 300:1
Bet you wish you'd stayed awake in math class now
Suggestion for further reading
Do a forum search for 'The Mathenoobics of Poker' series by DiamondDog