let a be an event within the sample space s, and let n(a)=a and n(s)=s. use the complements principle of…

let a be an event within the sample space s, and let n(a)=a and n(s)=s. use the complements principle of counting to find an expression for n(a). n(a) =

let a be an event within the sample space s, and let n(a)=a and n(s)=s. use the complements principle of counting to find an expression for n(a). n(a) =

Answer

Explanation:

Step1: Recall complements principle

The number of elements in the complement of an event $A$ (denoted as $A'$) in the sample - space $S$ is given by the formula $n(A')=n(S)-n(A)$.

Step2: Substitute given values

We are given that $n(A) = a$ and $n(S)=s$. Substituting these values into the formula, we get $n(A')=s - a$.

Answer:

$s - a$