This is the concept of probability, given that there are 8 red socks, 13 blues socks and 15 green socks, we are required to find that the first socks chosen will a red then a green; Here we shall proceed as follows; The events are dependent P(choosing a red socks )=8/36=2/9 P(choosing green socks after red)=15/35=3/7 Thus the probability of choosing red socks then a green socks without replacement will be: 2/9*3/7 =2/21