A box has 9 cards, 4 are labeled with numbers (1, 2, 3, 4) and 5 are labeled with letters (A, B, C, D, E). Two cards are drawn without replacement. What is the probability that the first card is labeled with a number and the second card is labeled with a letter?
Options
A
B
C
D
Answer & Analysis
Answer
B
Analysis
Question Analysis
This question is designed to test the application of the multiplication rule for dependent events in a simple classification scenario.
The main focus is on correctly counting the number of favorable outcomes for each event and applying the rule while considering the change in the sample space after the first draw.
Key Concept Explanation
Dependent events mean that the result of the first card draw influences the probability of the second draw.
The multiplication rule for dependent events, , is used.
Step-by-Step Solution
Calculate the probability of drawing a number - labeled card on the first draw:
There are 4 number - labeled cards out of 9 total cards, so .
Calculate the probability of drawing a letter - labeled card on the second draw given that a number - labeled card was drawn on the first draw:
After removing one number - labeled card, there are 8 cards left, and 5 of them are letter - labeled. So
Want More Practice Questions?
Access thousands of practice questions with detailed explanations on Scholardog.