How do you simplify #((n-k)!) /( n!)#? Precalculus The Binomial Theorem Factorial Identities 1 Answer Topscooter Dec 18, 2015 #((n-k)!)/(n!) = 1/((n-k+1)!)# Explanation: You simply develop #n!# and #(n-k)!#. #n-k < n# so #(n-k)! < n!# and #(n-k)!# divides #n!#. All the terms of #(n-k)!# are included in #n!#, hence the answer. Answer link Related questions What is a factorial? How do I find the factorial of a given number? How can the factorial of 0 be 1? How do I do factorials on a TI-84? What are factorials used for? What factorial equals 720? What is the factorial of 0? What is the factorial of 10? What is the factorial of 5? What is the factorial of 9? See all questions in Factorial Identities Impact of this question 4101 views around the world You can reuse this answer Creative Commons License