An examination is given to a class of 50 students. 5 got perfect scores.

What is the probability that a student who is picked at random from a group, is a student who got perfect score?

What is the probability that a student who is picked at random from a group, is a student who did not get a perfect score?

Click to Show/Hide Solution for #1

\[
P_{\text{Perfect Score}} = \frac{\text{Number of Students with a Perfect Score}}{\text{Total Number of tudents}}
\]
\[
P_{\text{Perfect Score}} = \frac{5}{50}
\]
\[
P_{\text{Perfect Score}} = 10\% \leftarrow \text{answer}
\]

Click to Show/Hide Solution for #2

\[
P_{\text{Not Perfect Score}} = \frac{\text{Number of Students with a Non-Perfect Score}}{\text{Total Number of tudents}}
\]
\[
P_{\text{Not Perfect Score}} = \frac{45}{50}
\]
\[
P_{\text{Not Perfect Score}} = 90\% \leftarrow \text{answer}
\]