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

Answer

To solve the problem of finding the probability of getting at least two tails when three coins are tossed, we can follow these steps:

### Step 1: Determine the total number of outcomes
When three coins are tossed, each coin has 2 possible outcomes: heads (H) or tails (T). Therefore, the total number of outcomes when tossing 3 coins is calculated as follows:

\[ \text{Total outcomes} = 2^3 = 8 \]

### Step 2: List all possible outcomes
The possible outcomes when tossing three coins are:
1. HHH
2. HHT
3. HTH
4. THH
5. HTT
6. THT
7. TTH
8. TTT

### Step 3: Identify favorable outcomes for at least two tails
We need to find the outcomes that have at least 2 tails. The outcomes that satisfy this condition are:
1. HTT (2 tails)
2. THT (2 tails)
3. TTH (2 tails)
4. TTT (3 tails)

Thus, the favorable outcomes are HTT, THT, TTH, and TTT, which gives us a total of 4 favorable outcomes.

### Step 4: Calculate the probability
The probability of an event is given by the ratio of the number of favorable outcomes to the total number of outcomes. Therefore, the probability of getting at least 2 tails is:

\[ P(\text{at least 2 tails}) = \frac{\text{Number of favorable outcomes}}{\text{Total outcomes}} = \frac{4}{8} = \frac{1}{2} \]

### Final Answer
The probability of getting at least two tails when three coins are tossed is \(\frac{1}{2}\).

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