# Random variable conditioning

## Homework Statement

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).

## Homework Equations

X~Exponential(2) means that its a exponential distribution integrated from -inf to inf, then sub lambda as 2.

## The Attempt at a Solution

the answer is 2/5 which is given but i dont get that... here is my prof's solution somehow he got 2/5
http://i.imgur.com/PCgDI.jpg

I don't understand how to get it, i end up getting infinity in the last step

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## Answers and Replies

nvm i figured it out