I am almost lost with this problem since I have a very basic idea about joint probabilities.Random variables X and Y are uniformly distributed in the triangular region $\displaystyle 0<=y<=x<=1$. Find fxy(x,y), the joint probability density function of X and Y.

Qn

my question is am I allowed to take conditional probabilities of X and Y are also uniformly distributed ?

descriptive answer will be highly appreciated.