Question

Charlie has a bent coin. The probability of tossing a "head" is 2/3. If he tosses the coin 5 times, what is the probability of tossing at least 3 "heads"?

Answer 1

probability of him getting 0 heads:
(1/3)^5

1 heads (assuming that order doesn't matter):
2/3*(1/3)^4

2 heads (assuming that order doesnt matter agian):
(2/3)^2*(1/3)^3

now the odds of him getting at least 3 heads is
1 - all the probabilities

Answer 2

why would you not include the probability of getting 3 heads in (all the probabilities)

Answer 3

i thougth it would be easier to go with the route of finding out when would he get 0 heads, 1 heads, and 2 heads then subtracting it from 1.

lets say the probabilitiy of him gettin AT LEAST 3 heads is P(x)
and then lets say that the probability of him getting NO MORE than 2 heads is Q(x)

P(x) = 1- Q(x)

Answer 4

I get it! Thank you!

Answer 5

anytime :D