Answer:
C.

Explanation:
We have been given a table showing rates of time taken by Judy and Sam to complete a puzzle.
We can see from our given table that Sal's rate is r. We are told that Judy completes a puzzle by herself, it takes her 3 hours. working with Sal, it only takes them 2 hours.
Since Judy completes the puzzle in 3 hours, so part of puzzle completed by Judy in one hour would be
, therefore, correct choice is option C.