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: Enumerate all potential results of flipping two coins.
The potential results are: 1. HH (Head, Head) 2. HT (Head, Tail) 3. TH (Tail, Head) 4. TT (Tail, Tail)

Step 2: Identify the desired outcomes.
The desired outcomes are those showing at least one head: HH, HT, and TH. This yields 3 desired outcomes.

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

Step 4: Final determination.
The probability of obtaining at least one head when flipping two coins is \( \frac{3}{4} \).