find an example for random variables X,X',Y,Y' with the following characteristics:
a)X and X' have the same distribution
b)X+Y and X'+Y' have the same distribution
c)Y and Y' do not have the same ditribution
a)X and X' have the same distribution
b)X+Y and X'+Y' have the same distribution
c)Y and Y' do not have the same ditribution