Question

Three coins are tossed together. The probability that at least one head comes up is

• A. \(\dfrac{3}{8}\)
• B. \(\dfrac{7}{8}\)
• C. \(\dfrac{1}{8}\)
• D. \(\dfrac{3}{4}\)

Hint:

To find the probability of "at least one", subtract the probability of "none" from 1.

Answer 1

The Correct Option is B

Given:
Three coins are tossed together.
Find the probability that at least one head appears.

Step 1: Total possible outcomes
Each coin has 2 outcomes (Head or Tail).
Total outcomes for 3 coins = \(2^3 = 8\).

Step 2: Find probability of complementary event (no heads)
No heads means all tails.
Number of ways = 1 (TTT)
Probability of no heads = \(\frac{1}{8}\).

Step 3: Calculate required probability
Probability of at least one head = \(1 - \text{Probability of no heads}\)
\[ = 1 - \frac{1}{8} = \frac{7}{8} \]

Final Answer:
\[ \boxed{\frac{7}{8}} \]