Question

What is the probability of flipping a coin 3times and getting 3tailsin a row?

Answer 1

1/8

Explanation:

To calculate the probability you have to name all possible results first. If you mark a result of a single coin flip as H for heads or T for tails all results of 3 flips can be written as:

Ω = { ( H , H , H ) , ( H , H , T ) , ( H , T , H) , ( H , T , T ) , ( T , H , H ) , ( T , H , T ) , ( T ,T , H ) , ( T , T , T ) }

Each triplet contains results on 1st, 2 nd and 3 rd coin. So you can see that in total there are 8 elementary events in Ω.

| Ω | = 8

Now we have to define event A of getting tails three times.

The only elementary event which satisfies this condition is ( T , T , T ) so we can write that:

A = { ( T, T , T ) }

| A | = 1

Now according to the (classic) definition of probability we can write, that:

P ( A ) = | A|/ | Ω | = 1 /8

So finally we can write the answer:

The Probability of getting 3 tails in 3 coin flips is 1 /8 .

Answer 2

1/8

Explanation:

The probability of getting tails on a single flip is 1/2.

Each of the flips is an independent event so you must multiply the probability of getting tails on each flip together.

So, your answer will look like this

`(1)/(2)` x
`(1)/(2)` x
`(1)/(2)` ; which equals;

1/8