Question

Find the probability of rolling an odd number when you roll an ordinary die. Express this probability as a percent.

• A. $\frac{1}{2}$ or $50\%$
  
• B. $\frac{1}{3}$ or $33.3\%$
  
• C. $\frac{1}{4}$ or $25\%$
  
• D. $\frac{1}{5}$ or $20\%$
  

Answer 1

The correct option is A $\frac{1}{2}$ or $50\%$


The possible odd numbers when a die is rolled are $1,3$ and $5$.

Number of favorable outcomes $=3$

Total number of outcomes $=6$

The probability $\text{P(Odd)}$ of rolling an odd number is:

$\text{P(Odd)}=\frac{\text{Number of favorable outcomes}}{\text{Total number of outcomes}}$

$\text{P(Odd)}=\frac{3}{6}$

$\text{P(Odd)}=\frac{1}{2}$
$\text{Probability in percent = Probability in decimal or fraction}\times 100$
$\text{Probability in percent}=\frac{1}{2}\times 100=50$
$\text{P(Odd)}=\frac{1}{2}=50\%$

The probability of rolling an odd number when a die is rolled is $\frac{1}{2}$ or $50\%$.

Therefore, option (a.) is the correct answer.