Answer:
Hence, the probability of rolling a 4 exactly 2 times is:
[tex]\dfrac{1}{6}\times \dfrac{1}{6}\times \dfrac{5}{6}\times \dfrac{5}{6}\times \dfrac{5}{6}\times \dfrac{5}{6}\times \dfrac{5}{6}=\dfrac{5^5}{6^7}[/tex]
Step-by-step explanation:
It is given that:
Thuy rolls a number cube 7 times.
so the total outcomes are: 6.
Also it is asked to find the probability of rolling a 4 exactly 2 times.
So it could be done by the method that:
[tex]\dfrac{1}{6}\times \dfrac{1}{6}\times \dfrac{5}{6}\times \dfrac{5}{6}\times \dfrac{5}{6}\times \dfrac{5}{6}\times \dfrac{5}{6}[/tex]
( where [tex]\dfrac{1}{6}[/tex] denotes the probability of rolling a 4 and [tex]\dfrac{5}{6}[/tex] denotes the probability of rolling a number other than 4 ).
Hence, the probability of rolling a 4 exactly 2 times is:
[tex]\dfrac{1}{6}\times \dfrac{1}{6}\times \dfrac{5}{6}\times \dfrac{5}{6}\times \dfrac{5}{6}\times \dfrac{5}{6}\times \dfrac{5}{6}=\dfrac{5^5}{6^7}[/tex]
