A garage knows that they have three charged and two dead batteries placed together by mistake. The random variable X is the number of batteries that have to be tested before all batteries are correctly identified as dead or charged.

I have constructed a tree diagram of (Correctly identfied and not correctly identified) but i don't know whether this right step in solving the question. Also, I dont know what values to put in for the probability.

[After it, I also need to the a table for the probablity function of x..but i dont know how] (Worried)