Final answer:
To find the prime factors of 225, divide it by prime numbers starting from 2. The prime factors used for the code in September could be 3, 3, 5, and 5.
Step-by-step explanation:
In September, the 4th digit of the code number is two more than the 4th digit of the code number based on the prime factors of 225.
To find the prime factors of 225, we divide it by prime numbers starting from 2.
225 ÷ 2 = 112 remainder 1
112 ÷ 2 = 56 remainder 0
56 ÷ 2 = 28 remainder 0
28 ÷ 2 = 14 remainder 0
14 ÷ 2 = 7 remainder 0
Since 7 is a prime number, the prime factors of 225 are 3, 3, and 5.
Based on the information given, the 4th digit of the code number is 3, and the 4th digit of the code number based on the prime factors of 225 is 3 + 2 = 5. Therefore, the prime factors used for the code in September could be 3, 3, 5, and 5.