to pick one red sock

to pick one blue sock

Since we are replacing the socks the events are independant so we multiply the probibilites together

since there are three different ways we can draw 2 red and 1 blue {r,r,b} or {r,b,r} or {b,r,r} we multiply our prob by 3

for two use the same process to find the prob of 3 red socks. then add the answer from part 1 to this answer.

Without replacement

use the same as above for the 2nd part