Question

A person is selected at random. What is the probability that the person was NOTborn on a Monday? (Remember there are seven days in a week) Express youranswer as a percent. If necessary, round your answer to the nearest tenth of apercent.85.7%20.0%80.0%14.3%

Answer 1

Probability that a person was NOT born on a Monday

Let's assume that being born each day has the same probability.

Since there are 7 days in one week, the probability that the person was NOT born on a Monday means that the person was born on any of the other 6 days.

Then

`P(\text{NotMonday)}=\frac{d\text{ays on which the person }could\text{ have been born}}{\text{total number of days in a week }}`

Then,

`\begin{gathered} P(\text{NotMonday)}=\frac{d\text{ays on which the person }could\text{ have been born}}{\text{total number of days in a week }} \\ \downarrow \\ P(\text{NotMonday)}=(6)/(7)\cong0.857 \end{gathered}`

We multiply it by 100 in order to transform into a percentage:

0.857 = 0.857 x 100% = 85.7%

Answer: A. 85.7%