Question

3 fair coins are tossed. What is the probability that at least one is a tail (enter the probability as a fraction.)

Answer 1

First, you should find:

Probability of NOT getting a tail in 3 coin toss:

$(\frac{1}{2})^3=\frac{1}{8}$

After that, you should find the probability of getting at least one tail in 3 fair coins tossed

$1-\frac{1}{8}=\frac{8-1}{8}=\frac{7}{8}$

Answer: 7/8