A deck of five cards (each carrying a distinct number from 1 to 5) is shuffled thoroughly. Two cards are then removed from the deck, one at a time. What is the probability that the two cards are selected with the number of the first card being one higher than the number on the second card?
- A. 1/5
- B. 4/25
- C. 1/4
- D. 2/5
Answer: A. 1/5
Explanation: Total ordered pairs of cards selected without replacement from {1,2,3,4,5} is 5 × 4 = 20. Favorable pairs (first = second + 1) are (2,1), (3,2), (4,3), (5,4), giving 4 pairs. Probability = 4/20 = 1/5.