I am going to assume that order does not matter.
All the fives and 3 out of the 4 jacks - only one jack is missing so there are 4 combinations of cards that fit this description.
there are 52C7 possible combinations with no restrictions.
nCr(52,7) = 133784560
so that is
P(3 jacks and 4 fives) = 4 / 133784560
I am going to assume that order does not matter.
All the fives and 3 out of the 4 jacks - only one jack is missing so there are 4 combinations of cards that fit this description.
there are 52C7 possible combinations with no restrictions.
nCr(52,7) = 133784560
so that is
P(3 jacks and 4 fives) = 4 / 133784560