1.1 problem 1(a)
  1.2 problem 1(b)
  1.3 problem 1(c)
  1.4 problem 1(d)
  1.5 problem 1(e)
  1.6 problem 1(f)
  1.7 problem 2(a)
  1.8 problem 2(b)
  1.9 problem 2(c)
  1.10 problem 2(d)
  1.11 problem 2(e)
  1.12 problem 3(a)
  1.13 problem 3(b)
  1.14 problem 3(c)
  1.15 problem 3(a)
  1.16 problem 4(a)
  1.17 problem 4(b)
  1.18 problem 4(c)
  1.19 problem 4(d)
  1.20 problem 5(a)
  1.21 problem 5(b)
  1.22 problem 5(c)
  1.23 problem 5(d)