Suppose there are two independent events A and B. The probability that A or B happens is $P_A(t)$ and $P_B(t)$ respectively where $t$ represents the time duration. The probability increases as time duration increases.

Assuming there is a time duration $0\rightarrow T$. What's the probability that event A happens and then B happens in time duration $0\rightarrow T$?

Suppose there are two independent events A and B. The probability that A or B happens is $P_A(t)$ and $P_B(t)$ respectively where $t$ represents the time duration. The probability increases as time duration increases. Both events can happen many times.

Assuming there is a time duration $0\rightarrow T$. What's the probability that event A happens and then B happens in time duration $0\rightarrow T$? In other words, what's the probability that we can find a event series $A,B$ in the duration $T$.