Emily is organizing her closet. She has 15 shirts left to hang but has space in one section for 6 shirts. How many ways could she hang shirts in that section?

Evaluate the given expression. ${}_9{P}_4$

You want to arrange the books on your bookshelf by color. How many different ways could you arrange 12 books if 4 of them have a blue cover, 3 are yellow, and 5 are white?

How many ways are there to arrange the letters in the word CALCULUS?

Evaluate the given expression. ${}_{11}{C}_7$

Find the term indicated in each expansion. (x − 1/2)⁹; fourth term

Find the term indicated in each expansion. (x² + y³)⁸; sixth term

Find the term indicated in each expansion. (x − 1)⁹; fifth term