Answer
$\frac{(x+2)(x+1)}{2}$
Work Step by Step
Use the combination formula:
$_{x+2}C_x=\frac{(x+2)!}{2!x!}=\frac{(x+2)(x+1)}{2}$
Elementary Statistics: A Step-by-Step Approach with Formula Card 9th Edition
by Bluman, Allan
Published by
McGraw-Hill Education
ISBN 10:
0078136334
ISBN 13:
978-0-07813-633-7
Chapter 4 - Probability and Counting Rules - 4-4 Counting Rules - Extending the Concepts - Page 238: 71
Update this answer!
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.
