Question

Among every 8 units of a product, one is likely to be defective. If a consumer has ordered 5 units of that product, then the probability that atmost one unit is defective among them is \

• A. \( \frac{15}{8} (\frac{7}{8})^6 \)
• B. \( \frac{57}{8^8} \)
• C. \( \frac{36}{8^5} \)
• D. \( \frac{3}{2} (\frac{7}{8})^4 \)

Hint:

In binomial probability, "at most k" means \( P(X=0) + P(X=1) + ... + P(X=k) \). "At least k" means \( P(X=k) + P(X=k+1) + ... + P(X=n) \). Recognizing these phrases is key to setting up the correct sum of probabilities.

Answer 1

The Correct Option is D