Chapter 10.4, Problem 8E

To determine

Tocalculate:

The probability that student or student’s friend win the election.

Answer to Problem 8E

The probability that student or student’s friend win the election is $0.70$ .

Explanation of Solution

Given information:

Student’s winning chances $=45\%$

Student’s friend’s winning chances $=25\%$

Formula used:

  $P\left(AorB\right)=P\left(A\right)+P\left(B\right)$

Calculation:

Assume that, event $A$ denote a student win the running for class president and event $B$ denote friend of the student win the running for the class president. Since, events $A$ and $B$ are disjoints, then probability of $A$ or $B$ is given follows:

  $P\left(AorB\right)=P\left(A\right)+P\left(B\right)$

Therefore, the required probability is as follows:

  $\begin{array}{l}P\left(AorB\right)=0.45+0.25\\ =0.70\end{array}$

Hence, the answer is $0.70$ .

So, the probability that student or student’s friend win the electionis $0.70$ .