these correct N may I see the forumla please!

[shutupndeal]

Pocket pair improving to three of a kind on flop
1 in 8
Im not sure how to do this one.


2 random cards (starting hand)improving to 1 pair on flop
1 in 3.125
Im not sure how to show this BUT I say its6.5-1 and then divided by 2 right? More like 3.250 ?



Gutshot straight draw hitting by river
1 in 6

Wouldnt the actual odds of the gutshot be 1 in 6.5-1?
Theres 13 cards no?