What is the probability of being dealt a 9,10,jack, queen, king all in the same suit?

Hmm, alright

not necicarily in that order
probblity=desired outcomes/total possible outcomes

so

4 suits

so the first card is either a 9,10, jack, queen or king of any suit
5*4=20 (4 suits) so 20/52 is probability

now we gots to pick the same suit
now we has 4 cards out of the 51 left that we want
4/51

now we has 3/50

then 2/49

then 1/48

multiply them all together

20/52 times 4/51 times 3/50 times 2/49 times 1/48=480/311875200=1/649740

probablity is 1 in 649740 or about 0.000153% chance