Question

If you flip three fair coins, what is the probability that you'll get all three tails?

Answer 1

Let H be the event that head occurs and let T be the event that tail.

Then the complete Sample Space,S for the experiment given in the question is:

S={ HHH, HHT, HTH, THH, HTT, THT, TTH, TTT}

As we can see the total number of elements in the sample space is 8. Let us represent this by the letter N.

Therefore, N=8

Now, the event of interest to us is TTT and it's occurrence is once. Let represent this by the letter E.

Therefore, E=1

Thus, the probability of the event E occurring is given as:

`P(E)=(E)/(N)=(1)/(8)`

`(1)/(8)` is the required answer. This can be represented in percentage too as:

`(1)/(8)* 100=12.5`%

Answer 2

probability of getting a tail = 1/2
pr(3 Tail) = 1/2 × 1/2 × 1/2
= 1/8