The non-negative integers are divided into three groups as follows:

A = {0,3,6,8,9...}, B = {1,4,7,11,14...}, c={2,5,10,13...}

Explain ? I have no idea how to proceed.

  • $\begingroup$ I am sorry, but those aren't groups. They are sets. Groups must have an associative binary operation, an identity, and inverses for each element. $\endgroup$
    – Justin
    Commented Oct 19, 2014 at 22:14
  • 7
    $\begingroup$ @Quincunx Your statement is precisely correct, but I think it's pretty clear that he's using the term group in an informal sense. $\endgroup$
    – wchargin
    Commented Oct 20, 2014 at 1:21
  • $\begingroup$ @WChargin Unfortunately, I get really bugged when I see improper (informal) language... $\endgroup$
    – Justin
    Commented Oct 20, 2014 at 18:15
  • $\begingroup$ @Quincunx Maybe it's formal language in a discipline other than yours. Or perhaps it's a literal translation of formal terminology in the OP's native language. In any case, I think perfectly precise terms wouldn't add anything useful to this question. $\endgroup$
    – Muqo
    Commented Oct 21, 2014 at 12:35

1 Answer 1


A contains integers (typically) composed of just curved lines when written. B contains integers (typically) composed of just straight lines when written. And C contains integers (typically) composed of both curved and straight lines.

kaine has pointed out that "12" seems to be missing. If you do a web search for the following, you can see that kaine is likely correct: "0, 3, 6, 8, 9" "1, 4, 7, 11, 14", "2, 5, 10, 12, 13"

  • $\begingroup$ Nice one, didn't see this coming $\endgroup$
    – Fabinout
    Commented Oct 20, 2014 at 12:27
  • 4
    $\begingroup$ So 12 is missing from c? $\endgroup$
    – kaine
    Commented Oct 20, 2014 at 18:31

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.