math and probability

Question

A jar contains 2 red and 8 blue marbles.

If you pick 4 marbles one at a time, putting each one back after you pick it, what is the probability the first two are red and the last two are blue?

If you pick two marbles, one after the other, without putting the first one back, what is the probability the first is red and the second is blue?

Answer 1

2 red 8 blue

pick 4 with replacement

odds first 2 are red, last 2 are blue

1/5 x 1/5 x 4/5 x 4/5 = 16/625 = 2.56 %

but without replacement odds are

2/10 x 1/9 x 8/8 x 7/7 = 1/45 = 2.22...%

once you get 2 red, it's certain you get 2 blue on the next two draws

but the problem is what is the probability of drawing without replacement and getting 1st red and then 2 blue

that = 2/10 x 8/9 x 7/8 = 56/360 = 28/180 = 14/90 = 7/45 = 15.55...%