Answer:
The largest number of gift bags that can be packed is:
9
Explanation:
To find The largest number of gift bags that can be packed, we need to find the greatest common divisor of these numbers.
Listing the prime factorization's for each number:
 171 = 3 x 3 x 19 
63 = 3 x 3 x 7 
27 = 3 x 3 x 3 
 As we can clearly see from the prime factorization the greatest common factor of these numbers is 9(3×3)
The largest number of gift bags that can be packed is:
9