I saw this in a television commercial yesterday for Trend Barber College.

Problem:
The hyphen is in the wrong place.

Explanation:
The number “9” alone is used as an adjective to modify the noun “months” (which does not modify anything else), so no hyphen should exist between these two.

The speaker in the commercial did not use “barber” to modify “stylist”; instead, he used “barber” and “stylist” together as a single word to identify the profession.

So a hyphen between these two words would be warranted.

Solution:
“BECOME A BARBER-STYLIST IN 9 MONTHS”