1. How does a set differ from a sequence?
In a set such as {1,2, 3, 4} the order of the members of the set is not important. e.g. {1, 2, 3, 4} = {4, 3, 2, 1}
In a sequence <1, 2, 3, 4, ...> the order of the members of the sequence has to remain the same. <1, 2, 3, 4, ...> ≠ <4, 3, 2, 1, ...>
2. Why do we need to study sets?
Sets offer a convenient way to organise items and can be very useful for illustrating solutions to equations and inequations, solving probability problems and logic puzzles.
