Two events $E$ and $F$ satisfy $P(E\cap F)=0$. State the technical term used to describe the relationship between these two events.

A diagnostic test uses two separate chemical indicators, Alpha ($A$) and Beta ($B$), to detect a specific enzyme. Indicator $A$ activates independently of indicator $B$.

The probability that indicator $A$ activates is $\frac{3}{4}$. The probability that at least one of the indicators activates is $\frac{17}{20}$.

Determine:

$P(B)$

$P(A\cap B^{\prime })$

$P(A^{\prime }|B)$