To multiply mix numbers and a normal fractions you make the mix number into a improper fraction. To do that you multiply the bottom and add the top. Here are the answers:
1/2 x 5 1/2 = 2 3/4
3 3/4 x 1/2 = 1 7/8
1/2 x 3 1/3 = 1 1/6
3/4 x 3 1/6 = 3 1/8
2/1 x 1 1/7 = 2 2/3