Aapki roochi kya hai? It depends on the noun's gender..Roochi is feminine so you need to use aapKI before it.. Let me give you another example: Aapka naam kya hai ? Here, since Naam is masculine, you have to use aapKA (Remember, no matter who you ask this question to, a girl or a boy, always ask aapKA naam kya hai?) AapKE is different than aapki and aapka..Eg: Aapke kamre mein koi rehta hai..meaning..someone lives in your room..Aapke kamre mein=In your room.. Hope I didn't confuse you!

this one too http://www.italki.com/answers/question/98530.htm

Gud question, please go to http://www.italki.com/answers/question/69243.htm replace aapka with mera, aapke with mere and aapki with meri instead of "my" it becomes "your"