j, b, and c are positive integers. If j, b, and c are assembled into the six-digit number jbcjbc, which one of the following must be a factor of jbcjbc?  Choices:
A) 16	B) 13	C) 5	D) 3	E) none of the above
Plug in some values and check -   jbcjbc = 123123   Not divisible by 16 and 5   let jbcjbc = 125125   Not divisible by 3   Only option (B) and (E) is left in both the cases...   Check once more to marke (13) as correct answer   let jbcjbc = 135135   Again divisible by 13   So, mark answer as (13) 13
<result>B</result>
j, b, and c are positive integers. If j, b, and c are assembled into the six-digit number jbcjbc, which one of the following must be a factor of jbcjbc?