Answer:
11
Step-by-step explanation:
15+18=33
33/3=11
IF DENISE CUTS EACH IN 3 FEET , SHE CAN GET 11 PIECES
IF SHE CUTS IN 11 FEET , SHE CAN GET 3 WOOD PIECES
THE SIZE OF SHELVES IS NOT MENTIONED SO THIS ANSWER IS CORRECT
Answer is D on edge