Respuesta :
Answer: The required probability is 50%.
Step-by-step explanation: Given that Tommy has a piece of toast that has butter on one side.
The first two times dropped the piece, it landed with the butter side up.
We are to find the probability that the piece will have landed butter side up a total of three times, if he drops it two more times.
For the butter side to be landed up three times, one of the last two drops must land butter side up.
Let, 'S' denotes the sample space for the experiment of dropping the piece for the last two times, then
n(S) = 2.
Let, 'B' be the event of getting one of the last two drops landed butter side up, then
n(B) = 1.
Therefore, the probability of getting one of the last two drops landed butter side up will be
[tex]P(B)=\dfrac{n(B)}{n(S)}=\dfrac{1}{2}=50\%.[/tex]
Thus, there is 50% probability of landing butter side up a total of three times.
