Office challenge: help this user quickly rearrange slides in a PowerPoint presentation

This week, test your PowerPoint skills by helping a PowerPoint user rearrange slides quickly.

Suppose a user, who isn't familiar with PowerPoint, wants to rearrange a few slides. She doesn't actually use PowerPoint, she's just filling in for someone. She's on the phone and she just can't seem to drag the slides using the Slides tab. Can you help?