X and Y have joint CDF of the form F xy 05xy xy if 0

X and Y have joint CDF of the form:

F (x,y) = 0.5xy (x+y) if 0 <x<1, 0 <y <1

0.5x (x+1) if 0 <x <1, 1 <= y

0.5y (y+1) 1 <=x, 0 <y <1

1 if 1 <=x, 1 <=y

0 else

Find the joint pdf

B) find P [X <= 0.5, y <= 0.5]

C) find P [X <Y]

D) find P [X+Y <=1.5]

E) Find P [X+Y <=0.5]