All the factors of a number except 1 and the number itself are called the Proper Factors of that number.
Factor of a number is same as that of its divisor, but in case of proper divisor we include 1 also.
The factors of 16 are 1, 2, 4, 8, and 16. The factors 2, 4, 8 excluding 1 and 16 are called the proper factors of 16.
A. 2, 3, 4, 6, 9, 12, 18
B. 1, 2, 3, 4, 6, 9, 12, 36
C. 2, 3, 4, 6, 9, 12, 36
D. 2, 3, 4, 6, 8, 9, 12, 18
Correct Answer: A
Step 1: The factors of 36 are 1, 2, 3, 4, 6, 9, 12, 18, and 36.
Step 2: Proper factors of 36 are 2, 3, 4, 6, 9, 12, and 18. [Exclude the factors 1 and itself.]
Q1: What are the proper factors of 12?
Q2: Which of the following is NOT a proper factor of 24?
Q: What is the difference between a factor and a proper factor?
A: A factor of a number includes 1 and the number itself, while a proper factor excludes these two.
Q: Does every number have proper factors?
A: No, prime numbers only have 1 and themselves as factors, so they have no proper factors.