Question

If we twice flip a balanced coin, what is the probability of getting at least one head?

• A. \( \frac{1}{4} \)
• B. \( \frac{2}{4} \)
• C. \( \frac{1}{6} \)
• D. \( \frac{3}{4} \)

Hint:

For \( n \) coin flips, the probability of getting at least one head is the complement of the probability of getting no heads.

Answer 1

The Correct Option is D

Step 1: List all possible outcomes of two coin flips.
The possible outcomes are: 1. HH (Head, Head) 2. HT (Head, Tail) 3. TH (Tail, Head) 4. TT (Tail, Tail)

Step 2: Find the favorable outcomes.
The favorable outcomes are those with at least one head: HH, HT, and TH. Therefore, there are 3 favorable outcomes.

Step 3: Calculate the probability.
The probability is the ratio of favorable outcomes to total outcomes: \[ P(\text{at least one head}) = \frac{3}{4} \]

Step 4: Conclusion.
The probability of getting at least one head in two coin flips is \( \frac{3}{4} \).