There are numerous information's of immense importance already given in the question. Based on these information's the answer to the question can easily be found. Let us first write down all the information's given
Quantity of carpeting required for the apartment = 36 square yards
Number of similar apartments that need carpeting = 25
Number of yards required for
carpeting 25 identical apartments = (36 * 25) square yards
= 900 square yards
So 900 square yards of carpeting is required to carpet 25 similar apartments.