Paper 2 · Probability ⏱ Tested in 1 exam question since 2018 Lesson 4 of 9

Probability 4 – Factorials

This tutorial is for members

Read the lesson notes free below — subscribe to watch the full worked video and download the PDF.

Subscribe for full access · €199/yr

You’ll learn

  • Evaluate factorials and interpret n! as the number of arrangements of n objects
  • Use the recursive rule n! = n × (n−1)! to peel factorials apart
  • Simplify factorial fractions like (n+2)!/n! by peeling and cancelling
  • Explain why 0! = 1

Most recent exam questions

  • 2018 P2 Q3(b)

💬 Stuck on something in this lesson?

Send your question with this lesson’s name attached — you’ll get a reply by email.