Need help with two questions ( SET OPERATORS and WINDOW FUNCTIONS )

I did 'Querying Microsoft SQL Server 2012 Jump Start' Course. But I got these two following questions wrong:

1)True or False: You use the INTERSECT operator to combine results from two SELECT statements. Only rows that appear in both results sets are displayed.

2)You need to create a SQL statement that distributes rows into a specified number of groups. For each row, you must return the number of the group to which the row belongs. Which ranking function should you use?

NTILE, RANK, DENSE_RANK, ROW_NUMBER.

Probably my English skills aren't so good as I thought. Can somebody tell me and explain the correct answer ? 

1) True

2) RANK and DENSE_RANK

Thank you