Answer:
50 times.
Step-by-step explanation:
We have been given that Elizabeth is going to flip a fair coin 100 times. We are asked to find the number of times the coin will land tails up.
Since we know that a fair coin has two equally likely possible outcomes and each flip has an equal chance of coming up heads or tails.
![\text{Probability}=\frac{\text{Number of favorable outcomes}}{\text{Total number of possible outcome}}](https://img.qammunity.org/2020/formulas/mathematics/high-school/lfyi23kttktx16zpdjkmg3ctujw7txvk8t.png)
![\text{Probability of getting tails in one flip}=(1)/(2)](https://img.qammunity.org/2020/formulas/mathematics/high-school/iaaag6jcb3xd0d8ywewbok74fa87ln3xrh.png)
To find the number of times the coin will land tails up we will multiply the probability of getting tails in one flip by the number of times coin was flipped.
![\text{Possible number of getting tails in 100 flips}=(1)/(2)* 100](https://img.qammunity.org/2020/formulas/mathematics/high-school/bkvurgvwrq96bppb08h38s9vz7y8ker6c3.png)
![\text{Possible number of getting tails in 100 flips}=50](https://img.qammunity.org/2020/formulas/mathematics/high-school/d7hysht9v9k5vcdkhcw06qxav2fxrofpeh.png)
Therefore, the coin will land about 50 times tails up in 100 flips.