The ordinal number for the number 15 in a sequence

पंद्रहवीं

English Usage: She finished in fifteenth place in the race.

Hindi Usage: वह दौड़ में पंद्रहवीं स्थान पर रही।

Relating to the ordinal number fifteen

पंद्रहवां

English Usage: This is my fifteenth birthday.

Hindi Usage: यह मेरा पंद्रहवां जन्मदिन है।