Question

At a fabric store, the probability that a customer buys thread is 0.15. The probability that a customer buys a needle given that the customer buys thread is 0.25.
Which statement is true?

A. Buying a needle and buying a thread are independent events.
B. Every customer who buys a thread also buys a needle.
C. Buying a needle and buying a thread are dependent events.
D. The probability that a customer buys a needle and thread is a 0.10.

Answer 1

Answer:

The correct statement is:

C. Buying a needle and buying a thread are dependent events.

Explanation:

The first statement is incorrect because the given events are dependent on each other because the probability that a customer buys a needle given that the customer buys thread is 0.25.

The second statement is incorrect because we cannot say all those who buy a thread also buy a needle.

The fourth statement is incorrect because the probability that a customer buys a needle and thread is $0.25 \times 0.15=0.0375$