Get average age of people

Basic Sum, Average, Min, Max

Aggregate starting with a seed

Use Aggregate to get sum of int array

Square second half of ints array

Concat two int arrays

OrderByDescending then TakeWhile

Partitioning operations SkipWhile and TakeWhile

Partitioning operation Skip

Quantifying Operations: Any, Contains and All

Use Except to get items that are in one collection but not in another

Use Union to get all items that appear in either of two collections

Use set operation, Intersect, to get distinct common items of two collections

Use set operation, Distinct, to get all distinct items

Use SequenceEqual method to deep compare two collections