jenna flips two pennies 105 times. how many times can she expect both coins to come up heads?
The chance of one coin landing on heads is 1 / 2.
Since Jenna flips two pennies you should multiply:
1 / 2 ∙ 1 / 2 = 1 / 4
105 ∙ 1 / 4 = 105 / 4 = 26.25
So, the answer is 26.25 times.
Approximately 26 times.
To determine how many times Jenna can expect both coins to come up heads, we can use probability.
When flipping two coins, there are four possible outcomes for each flip: Heads-Heads (HH), Heads-Tails (HT), Tails-Heads (TH), and Tails-Tails (TT).
Assuming the coins are fair, each of these outcomes has a 1/4 probability, or 0.25.
Since Jenna flips the coins 105 times, we can use the concept of expected value to estimate the number of times both coins will come up heads. Expected value is calculated by multiplying each possible outcome by its probability and summing them up.
Expected value = (probability of HH) * (number of flips)
Expected value of HH = 0.25 * 105 = 26.25
Therefore, Jenna can expect both coins to come up heads approximately 26.25 times. However, since we cannot have a fractional number of outcomes, it is more practical to say she would expect it to happen around 26 times.
To find out how many times Jenna can expect both coins to come up heads, we need to consider the probability of getting heads on each coin flip.
For a fair penny, the probability of getting heads is 1/2 (since there are two possible outcomes - heads or tails - and both are equally likely).
Since Jenna flips two pennies each time, the probability of getting heads on both coins is calculated by multiplying the probabilities of each individual coin flip.
So, the probability of getting heads on both coins is:
(1/2) * (1/2) = 1/4
Now, to find the expected number of times Jenna can expect both coins to come up heads, we multiply this probability by the total number of coin flips:
Expected number of times = Probability * Total number of flips
Expected number of times = (1/4) * 105
Expected number of times = 105/4
Expected number of times ≈ 26.25
Therefore, Jenna can expect both coins to come up heads approximately 26.25 times in 105 flips.