a and b are positive integers less than or equal to 9 and multiple of 4. If a and b are assembled into the seven-digit number abaabab, which of the following must be a factor of abaabab?
Choose the correct choice from the following answers:  A) 3  B) 4  C) 5  D) 7  E) 8
The last two digit of the number are ab. Both a and b are multiple of 4,thus the last two digits are divisible by 4, which makes the number abaabab divisible by 4. Thus 4 is always a factor of abaabab.   Answer: 4
<result>B</result>
a and b are positive integers less than or equal to 9 and multiple of 4. If a and b are assembled into the seven-digit number abaabab, which of the following must be a factor of abaabab?