Why is the group name SEVENTEEN?

I counted all the SEVENTEEN members and there were 13 members.

I don't think they're 17 years old.

531 12 6 years ago

pu1. I was curious, too

2018-12-16

pu2. 13 members, 3 units, 1 team
If you add it up to 17

2018-12-16

pu3. @2 Is that true? Is this just a joke?

2018-12-16

pu4. Count it well

2018-12-16

pu5. Count again

2018-12-16

pu6. an average age of 17

2018-12-16

pu7. The four of us are hiding

2018-12-16

pu8. I don't know what's real

2018-12-16

pu9. @2 This is official

2018-12-16

pu10. Three units of 13 members will become one team. SEVENTEEN

2018-12-16

pu11. I was going to make it with 17 people, but it's down to 13 people, but I think I just kept the name

2018-12-16

pu12. Thank you for letting me know

2018-12-16