Question
The number of triplets $(x, \mathrm{y}, \mathrm{z})$, where $x, \mathrm{y}, \mathrm{z}$ are distinct non negative integers satisfying $x+y+z=15$, is :
The number of triplets $(x, \mathrm{y}, \mathrm{z})$, where $x, \mathrm{y}, \mathrm{z}$ are distinct non negative integers satisfying $x+y+z=15$, is :