14.1 problem 1
14.2 problem 2
14.3 problem 3
14.4 problem 4
14.5 problem 5
14.6 problem 6
14.7 problem 7
14.8 problem 8
14.9 problem 9
14.10 problem 10
14.11 problem 11
14.12 problem 12
14.13 problem 13
14.14 problem 14
14.15 problem 15
14.16 problem 16
14.17 problem 17
14.18 problem 18
14.19 problem 19
14.20 problem 20
14.21 problem 21
14.22 problem 22
14.23 problem 23
14.24 problem 24
14.25 problem 25
14.26 problem 27
14.27 problem 29