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Q43 (CAPF/2022) Science & Technology › Basic Science (Physics, Chemistry, Biology) › Quantitative aptitude topics Answer Verified

A coin is tossed 3 times. The probability of getting exactly 2 heads is

Result
Your answer: —  Â·  Correct: B
Explanation

When a fair coin is tossed 3 times, the total number of possible outcomes in the sample space is 2^3 = 8. These outcomes are {HHH, HHT, HTH, THH, HTT, THT, TTH, TTT}. To find the probability of getting exactly 2 heads, we identify the favorable outcomes where 'H' appears exactly twice: {HHT, HTH, THH}. There are 3 such favorable outcomes. Using the classical definition of probability, which is the number of favorable outcomes divided by the total number of possible outcomes, the probability is 3/8. This can also be calculated using the binomial distribution formula P(X=k) = (n choose k) * p^k * (1-p)^(n-k), where n=3, k=2, and p=0.5, resulting in 3 * (1/2)^3 = 3/8.

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