emf_jay wrote:Plz Explain...
When a certain coin is flipped, the probability that it will land on heads is 1/2 and the probability that it will land on tails is 1/2. if the coin is flipped 3 times, what is the probability that all 3 results are the same ?? A. 1/8 B. 1/4 C. 3/8 D. 1/2 E. 7/8
The FIRST flip is irrelevant: the result can be heads or tails.
All that matters is what happens on the SUBSEQUENT flips.
P(2nd flip is the same as the first) = 1/2.
P(3rd flip is the same as the first 2 flips) = 1/2.
Since we want both events to happen, we multiply the fractions:
1/2 * 1/2 = 1/4.
The correct answer is
B.
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