This question could be answered in two different ways. Why does Pi survive exactly 227 days? He survives that long because he never gives up, figures out creative solutions to problems, and maintains an overall positive attitude about his dire situation. That answer would be true if Pi survived 226 days, 228 days, or any other number of days; therefore, it is also likely that this question is forcing the answer to consider the significance of the number 227. The number 227 isn't significant until you force into a fraction -- 22/7. 22/7 is the fraction version of the number Pi (3.141592653). Most readers aren't likely to make this connection, but it is a really neat piece of symbolism that the author has hidden in the story. Pi (the character) is a very intelligent kid, and he is likely to see the connection between his time at sea, the irrational number, and his name. For a kid like Pi, this seemingly random time at sea would further deepen his faith in a fully interconnected world and spiritual realm.