Underwear Company Job

A man went to an women underwear company for a job interview. The manager says,
"If you can answer these 3 questions right, the job is yours!
We pack our panties in 7 packs, 5-packs and 12 packs. Why?"
The man thinks for a moment and replies,
The 7-packs are for Sri Lankan women: one for each day of the week.
The 5-packs are for American women : one each for Monday to Friday, and they don't wear panties on weekends.
The 12-packs are for India women : one each for January, February, March April, May, June, July, August, September,October, November,December...
He got the job.....