a) 2/7
There are a total of 14 pairs of socks (4+2+8) so 14 is your denominator.
Then you take however many red socks there are and that is your numerator (4).
Then you simplify. 4/14 ; 2/7
b) 1/4
There are a total of 40 headbands (10+6+24) so 40 is your denominator.
Then you take however many red headbands there are and that is your numerator (10).
Then you simplify, 10/40 ; 2/8 ; 1/4
c) 15/28
You then add 2/7 and 1/4.