Final answer:
The probability is 1/4.
Step-by-step explanation:
To find the probability that a fair coin is flipped a multiple of three times before coming up heads, we need to consider the possible outcomes of the coin flips.
A fair coin has two possible outcomes: heads (H) or tails (T), each with a probability of 0.5.
If the coin is flipped once, there are two possible outcomes: H or T.
If the coin is flipped twice, there are four possible outcomes: HH, HT, TH, or TT.
If the coin is flipped three times, there are eight possible outcomes: HHH, HHT, HTH, HTT, THH, THT, TTH, or TTT.
We can see that there are two outcomes (HHT and THH) where the coin is flipped a multiple of three times before coming up heads.
Therefore, the probability is 2/8 or 1/4.