Counting Math Homework

Question

Amber has ten paintings and have room to display only three of them at a time on her wall. How many different ways could she do this?

Answer 1

Answer:

¹⁰C₃ = 10!/(10!-3!)*3!

= 10!/(7! x 3!)

= (10 x 9 x 8) / (3 x 2 x 1) -- 7! cancels out all the digits from 7 to 1 in 10!. 3! is left in the denominator

We end up with 720 / 6 = 120 combinations