page 87 exercise 1
page 87 exercise 2
page 90 exercise 2
page 93 exercise 1
page 94 exercise 2
page 94 exercise 3
pg93-1: replace 'for' with 'while'
page 96 exercise 2
page 98 exercise 1
page 98 exercise 2
page 100 exercise 1
page 100 exercise 2
pg100-1: added break; improve performance
page 103 exercise 2
page 105 exercise 1
page 110 exercise 2
page 112 exercise 1 - top
part 3 - final test
part 3 - comprehensive test