Question

Solution for how many tosses of a coin are needed so that the probability of getting at least one head is 0.875

Answer 1

.125
this is your answer

Answer 2

Answer:

3

Step-by-step explanation:

Let p = 0.875p=0.875 be the probability of getting at least one head. Let qq be the probability of getting all tails. It is logical that p + q = 1.p+q=1. The coin is fair, so after tossing nn times the probability of of getting all tails is q = 0.5^nq=0.5  

n

. So we get the equation:

0.875+0.5^n = 1 \quad \Longrightarrow \quad n = \log_{0.5}(1-0.875) = 30.875+0.5  

n

=1⟹n=log  

0.5

​  

(1−0.875)=3