设随机变量（X，Y）联合概率密度为f(x,y)=3x,0<=x<=1,0<=y<=x

设随机变量（X，Y）联合概率密度为f(x,y)=3x,0<=x<=1,0<=y<=x,f(x,y)=0,其余，求P(X<1/4|Y=1/8)和P(Y<1/8|X<1/4)
要具体解题步骤！！！急！！！

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答案行闷橡档旁见罩扒图

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