Four fair coins are to be flipped. What is the probability that all four will be heads or all four will be tails? Express your answer as a common fraction.
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
Four fair coins are to be flipped. What is the probability that all four will be heads or all four will be tails? Express your answer as a common fraction.
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
\frac{1}{8}
Four fair coins are to be flipped. What is the probability that all four will be heads or all four will be tails? Express your answer as a common fraction.
train