Difficulty: Easy
Correct Answer: 840
Explanation:
Introduction / Context:
Look for factor-based decay: consecutive divisions by 1, 2, 3, 4, 5 produce a tidy ladder from the start value.
Observation / Approach:
Step-by-Step Solution:
The missing second term equals 840 ÷ 1 = 840.
Verification / Alternative check:
All subsequent divisions neatly match the remainder of the given sequence.
Why Other Options Are Wrong:
Other values break the exact factorial-like division progression and will not land exactly on 420 after the next step.
Common Pitfalls:
Starting the division at 2; the pattern begins with ÷1 to include the repeated 840.
Final Answer:
840
Discussion & Comments