Question

There are 5 white pencils and 6 red pencils in a box. One pencil is selected at random and not replaced. Another pencil is randomly selected from the remaining pencils. Determine whether this event is independent or dependent. Explain your answer.

A. Independent; the first pencil does not affect the sample space for the second one.
B. Independent; there are fewer pencils to choose from the second time.
C. Dependent; the first pencil does not affect the sample space for the second one.
D. Dependent; there are fewer pencils to choose from the second time.

Answer 1

D

Explanation:

• You have 5 + 6 pencils, which is 11 pencils
• The probability you will get white is 5/11
• Prob you get red is 6/11
• If you pick up a pencil and do not replace it, you now only have 10 pencils left
• The prob you get a red or a white is dependent on what you picked up first