Use the formula for nCr to evaluate each expression. ₁₀C₆

Use the formula for _nC_r to evaluate each expression. ₄C₄

How many options are there for license plates with any three letters (A-Z) followed by any 3 numbers (0-9)?

Phone numbers are 10 digits long. How many possible phone numbers are there if the 1^st and 4^th numbers can't be 0?

A student formed a club at their school. They have 13 members, and need to elect a president, vice president, and treasurer. How many ways are there to fill these officer positions?

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?