If Judy completes a puzzle by herself, it takes her 3 hours. Working with Sal, it only takes them 2 hours.

A table showing Rate in part per hour, Time in hours, and Part of Project Completed. The first row shows Judy, and has, question mark, 2, and StartFraction 2 Over 3 EndFraction. The second row shows Sal, and has, r, r, and 2 r.
What is the missing value from the table that represents Judy's rate?

r
3 – r
StartFraction 1 Over 3 EndFraction.
3