There are C(8,2) ways to get two red socks and C(9,2) ways to get two blue socks. That C(8,2)+C(9,2) = 28+36 = 64 ways to succeed. There are C(17,2) = 136 ways to get any two socks. So the probability is 64 out of 136 orwhich reduces to Edwin
Another way: P[(red 1st AND red 2nd) OR (blue 1st AND red 2nd)] AND means multiply and OR means add: P(red 1st)×P(red 2nd) + P(blue 1st)×P(red 2nd)] =× + × = × + × = + = = Edwin