Basic Probability

A fair coin is used.

What’s the probability of:-

A. Flipping Two Consecutive Heads
B. Flipping Two Consecutive Tails
C. Flipping Two Consecutive Heads OR Flipping Two Consecutive Tails

A) 0.5 x 0.5

B) 0.5 x 0.5

C)(0.5 x 0.5) + (0.5 x 0.5)

A) 25%
B) 25%
C) 50%

Hi Tony

good to have you back on board fella.

As ADB says, it is a half chance multiplied by a half chance for either scenario. Which is, a quarter chance. And then 1/4 chance + 1/4 chance for the 2 consecutive heads OR tails option, if you are not fussy about whether you want a head or tail.

If you spend long enough at it, you will eventually get 10 heads or tails in a row, like that Derren Brown fella. But it took him about 14 hours of filming before he actually achieved this.

as per DB;

a: 25%
b: 25%
c: 50%

OK. Right.

So the chance of my flipping a Head on any one toss of the coin is 50% or 1 in 2. Which means, I’d need to flip the coin twice to, statistically, expect to get a head. Is that correct?

Possible outcomes:

H H
H T
T H
T T

=> probability of at least one head is 0.75, because all outcomes are equally likely.

yes.