nvm i figured it out
The question is Let X and Y be jointly absolutely continuous Random Variables. Suppose X~Exponential(2) and that P(Y>5|X=x)=e^(-3x). Compute p(Y>5).
The solution given by my prof is 2/5
here is a pic of his work written by me
I don't under the last step where 2/5 is calculated, i only get infinity...