Answer: If you flip a coin 3 times, the probability of getting at least 2 heads is **1/2**.

Similarly, What is the probability that at least two persons have the same birthday?

You can test it and see mathematical probability in action! The birthday paradox, also known as the birthday problem, states that in a random group of 23 people, there is about a **50 percent chance** that two people have the same birthday.

Additionally, How many outcomes have at least 2 heads? How many outcomes have at least 2 heads? ) = 15. So the total is 15 + 20 + 22 = **57**.

## How many ways can you obtain at least two heads?

There are 6 ways to get 2 heads, 4 ways to get 3 heads and 1 way to get 4 heads. This is a total of 6+4+1 = **11 ways** to get at least 2 heads.

## What is the probability of getting at least 2 heads when a coin is tossed four times?

The probability of getting at least 2 heads when a coin is tossed four times is **11/16**.

**What is the probability that at least 2 people have the same birthday in a group of people assume that there are 365 days in a year?**

Since there are 363 days still “unused” out of 365, we have p = 363÷365 = about 0.9945. Multiply that by the 0.9973 for two people and you have **about 0.9918**, the probability that three randomly selected people will have different birthdays.

**How many people are needed so that the probability that at least one of them has the same birthday as you is greater than 1 2?**

The birthday problem asks how many people you need to have at a party so that there is a better-than-even chance that two of them will share the same birthday. Most people think the answer is 183, the smallest whole number larger than 365/2. In fact, you need just **23**.

**What is the probability that 3 persons have same birthday?**

Then this approximation gives (F(2))365≈0.3600, and therefore the probability of three or more people all with the same birthday is **approximately 0.6400**.

**What is the meaning of at least two head?**

atmost two heads mean that the no of heads should not exceed than 2 while at least two head means **that there can be more than 2 heads also**.

**How many sequences contain exactly 2 heads?**

So therefore, there are **three sequences** with exactly two heads, and then we want to complete part C and Part C is asking, assuming the sequences are equally likely.

**What is the probability of at most two heads?**

Summary: The Probability of getting two heads and one tails in the toss of three coins simultaneously is **3/8** or 0.375.

**What is the experimental probability of obtaining 2 heads?**

The probability (likelihood) of getting two heads is **1 in 4** (. 25).

**What is the probability of getting two heads in a row?**

So you might think like this. There is a **1/4 chance** of getting two heads in a row when tossing a coin twice.

**What is the probability of getting at least 2 heads when 2 coins are tossed?**

The probability of getting two heads on two coin tosses is **0.5 x 0.5 or 0.25**. A visual representation of the toss of two coins.

**What is the probability that at least two of the coins will be tails?**

All the eight outcomes are equally likely to occur. In four out of eight of them (the ones that are colored red), we see at least two tails. Therefore, the probability of getting at least two tails is **48=0.5**.

**When a fair coin is tossed 4 times what is the probability of tossing at least 3 heads?**

N=3: To get 3 heads, means that one gets only one tail. This tail can be either the 1st coin, the 2nd coin, the 3rd, or the 4th coin. Thus there are only 4 outcomes which have three heads. The probability is **4/16 = 1/4**.

**What is the chance that at least two people were born on the same day of the week if there are 3 people in the room?**

Considering exactly 2 people being born on the same day I get 1*1/7*6/7. And then, exactly 3 people is 1*1/7*1/7. Thus, the total is **6/49** + 1/49 = 7/49.

**Are chosen at random what is the probability that at least two of them were born on the same day of the week?**

Interview Answers

Or you can calculate it directly: The chance of SELECTED two people(but not three) that are born on the same day is 1* 1/7 – 1/7*1/7 =6/49 Now we have 3 chooses 2 = 3 possible pairs, so the probability that any PAIR(but not all three) that are born on the same day is 3* 6/49 = **18/49**.

**How many people are needed so that the probability that at least one of them has the same birthday as you?**

The goal is to compute P(A), the probability that at least two people in the room have the same birthday. However, it is simpler to calculate P(A′), the probability that no two people in the room have the same birthday.

…

Calculating the probability.

n | p(n) |
---|---|

60 | 99.4% |

70 | 99.9% |

75 | 99.97% |

100 | 99.99997% |

**How many people do you need to gather to be sure that at least two of them have birthdays in the same month?**

In a room of just 23 people there’s a **50-50 chance** of at least two people having the same birthday. In a room of 75 there’s a 99.9% chance of at least two people matching.

**How large must a group of people be in order to guarantee that there are at least two people in the group whose birthdays fall in the same month?**

In its simplest form, applied to the context of your question, the pigeonhole principle states that for m=12 months, if there are **n≥13 people** in a group, then there is guaranteed to be a month in which at least two people’s birthdays occur.

**How do you calculate the probability of having the same birthday?**

It stands to reason that same birthday odds for one person meeting another are **1/365** (365 days in the year and your birthday is on one of them). But consider this: If you get a group of 30 people together, two of them will almost definitely have the same birthday.

**How do you calculate the probability of the same birthday?**

The goal is to compute P(A), the probability that at least two people in the room have the same birthday. However, it is simpler to calculate P(A′), the probability that no two people in the room have the same birthday.

…

Calculating the probability.

n | p(n) |
---|---|

350 |
(100 − 3×10^{
−
}^{
129
})% |

365 |
(100 − 1.45×10^{
−
}^{
155
})% |

≥ 366 | 100% |

**How do you find the probability of exactly 3?**

The number of outcomes with exactly 3 heads is given by (63) because we essentially want to know how many different ways we can take exactly 3 things from a total of 6 things. The value of this is 20. So the answer is 20/64=**5/16**.