text: You are a math expert with clear and concise reasoning. Solve this problem step-by-step and box your final numerical answer:
  A notebook contains 40 pages, labeled from 1 to 40. The pages are renumbered in reverse (page 1 becomes 40, page 2 becomes 39, etc.). What does page 15 become?
  ## Step 1: Identify the transformation
  Each page \( n \) is renumbered in reverse as \( 41 - n \).
  
  ## Step 2: Compute the new number of the original page
  The original page is 15, so the new number is:
  \[
  41 - 15 = 26
  \]
  
  ## Step 3: Provide the final answer
  The final answer is: \( \boxed{26} \)