A coin is thrown 3 times What is the probabilit... - JAMB Mathematics 2023 Question

To find the probability of getting at least one head in three coin tosses, we can use the complement rule. The complement of "at least one head" is "no heads," i.e., getting all tails.

The probability of getting tails in a single toss is \( \frac{1}{2} \), so the probability of getting tails in all three tosses is \( \left(\frac{1}{2}\right)^3 \).

Now, the probability of getting at least one head is the complement of getting all tails:

\[ P(\text{at least one head}) = 1 - P(\text{no heads}) \]
\[ P(\text{at least one head}) = 1 - \left(\frac{1}{2}\right)^3 \]
\[ P(\text{at least one head}) = 1 - \frac{1}{8} \]
\[ P(\text{at least one head}) = \frac{7}{8} \]