I defined a vector P that contains my probability distribution for a Dice

Roll, i.e. 6 equal probabilities for each outcome. (1/6, 1/6,1/6,1/6,1/6,1/6)

Now, I want to define a matrix/vector that contains random variables Xt to define another random variable T_5 such that P(T_5=t) = P{Xt is the first random variable with outcome 5}

In other words: I start my process of tossing a die and T_5 is the first time

a 5 is diced.

Should I define two random value generators over a range of values ? How do I achieve a relationship between T_5 and Xt?

How would I define it with an expression?