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# Three unbiased coins are tossed once. Find the probability of getting

Question:

Three unbiased coins are tossed once. Find the probability of getting at least 2 tails

Solution:

We know that,

Probability of occurrence of an event

$=\frac{\text { Total no.of Desired outcomes }}{\text { Total no.of outcomes }}$

Let $\mathrm{T}$ be tails and $\mathrm{H}$ be heads

Total possible outcomes = TTT, TTH, THT, HTT, THH, HTH, HHT, HHH

Desired outcomes are at least two tails. So, the desired outputs are

TTH, THT, HTT, TTT

Total no.of outcomes are 8 and desired outcomes are 4

Therefore, the probability of getting at least 2 tails $=\frac{4}{8}$

$=\frac{1}{2}$

Conclusion: Probability of getting at least two tails is $\frac{1}{2}$