Solve the puzzle with explanation?

Question

There is a club. There are many people who are members of that club. On the entrance of the club there is a guard. He gives club members a number when they want to enter. The club member gives him another number back, related to the first. If the guard thinks that the answer is correct then he allows them to enter into the club, otherwise does not.

First, a man A comes to the guard. The guard gives him the number 12. The man A responds with 6. The guard allows him to enter.

Second, a man B comes to the guard. The guard gives him the number 6. The man B responds with 3. The guard allows him to enter.

Third, a man C comes to the guard. The guard gives him the number 8. The man C responds with 4. The guard does not allow him to enter.

Can you tell, what would've been the correct response?

Answer 1

he should have answered 5. Its the number of letters in the question
(twelve six eight)

Answer 2

One possibility is that the correct sequence is to double the guard's number and add the digits together.

12 * 2 = 24, and 2 + 4 = 6. The first man enters.
6 * 2 = 12, and 1 + 2 = 3. The second man enters.
8 * 2 = 16, and 1 + 6 = 7. The third man says "4" and can't enter.

(Edited to add: the first response also works, and that's just an illustration that problems like this can have more than one answer. The third man should have hid in the bushes longer, waiting for more data, before he tried to sneak into the club. ;-) )

Answer 3

If the sum of two numbers is multiple of 9,
it will correct answer.
12+6=2*9
6+3=1*9
but
8+4=12 is not a multiple of 9

Answer 4

mfem.geo
Jay H
iyiogrenci
all are correct. In the last case the answer should be 1 as 8+1=9=1*9

Answer 5

Five...there are six letters in twelve (12), there are three letters in six (6) and there are five letters in eight

Answer 6

please e mail me the correct answer