2.1 problem Problem 1(a)
 2.2 problem Problem 1(b)
 2.3 problem Problem 1(c)
 2.4 problem Problem 1(d)
 2.5 problem Problem 1(e)
 2.6 problem Problem 1(f)
 2.7 problem Problem 1(g)
 2.8 problem Problem 1(h)
 2.9 problem Problem 1(i)
 2.10 problem Problem 1(j)
 2.11 problem Problem 1(k)
 2.12 problem Problem 1(L)
 2.13 problem Problem 1(m)
 2.14 problem Problem 1(n)
 2.15 problem Problem 1(o)
 2.16 problem Problem 2(a)
 2.17 problem Problem 2(b)
 2.18 problem Problem 2(c)
 2.19 problem Problem 2(d)
 2.20 problem Problem 2(e)
 2.21 problem Problem 2(f)
 2.22 problem Problem 2(h)
 2.23 problem Problem 3(a)
 2.24 problem Problem 3(b)
 2.25 problem Problem 3(c)
 2.26 problem Problem 3(d)
 2.27 problem Problem 5(a)
 2.28 problem Problem 5(b)
 2.29 problem Problem 5(c)
 2.30 problem Problem 5(d)
 2.31 problem Problem 5(e)
 2.32 problem Problem 5(f)
 2.33 problem Problem 10
 2.34 problem Problem 13
 2.35 problem Problem 15
 2.36 problem Problem 18(a)
 2.37 problem Problem 18(b)
 2.38 problem Problem 18(c)
 2.39 problem Problem 18(d)
 2.40 problem Problem 18(e)
 2.41 problem Problem 18(f)
 2.42 problem Problem 18(g)
 2.43 problem Problem 18(h)
 2.44 problem Problem 18(i)
 2.45 problem Problem 18(j)
 2.46 problem Problem 18(k)
 2.47 problem Problem 18(L)
 2.48 problem Problem 19(a)
 2.49 problem Problem 19(b)
 2.50 problem Problem 19(c)
 2.51 problem Problem 19(d)
 2.52 problem Problem 19(e)
 2.53 problem Problem 19(f)
 2.54 problem Problem 20(a)
 2.55 problem Problem 20(b)
 2.56 problem Problem 20(c)
 2.57 problem Problem 20(d)
 2.58 problem Problem 20(e)
 2.59 problem Problem 20(f)
 2.60 problem Problem 20(g)
 2.61 problem Problem 20(h)