Number series – fill the missing factorial term: 1, 1, 2, 6, 24, ?, 720 Recognize the factorial progression and supply the missing value.

Introduction / Context:This is a classic factorial series. Recognizing factorial landmarks (1!, 2!, 3!, …) helps you recover missing terms instantly, a common pattern in aptitude tests.

Given Data / Assumptions:

• List: 1, 1, 2, 6, 24, ?, 720.
• Recall n! = 1*2*…*n, with 0! = 1 by convention.

Concept / Approach:Map each term to factorials in order: 0!, 1!, 2!, 3!, 4!, 5!, 6!. The gap clearly corresponds to 5!.

Step-by-Step Solution:

Verification / Alternative check:Continuity of factorial growth (rapidly increasing values) and exact match at 6! confirms correctness.

Why Other Options Are Wrong:

Common Pitfalls:Confusing double factorial or powers for factorials; the given endpoints anchor factorial interpretation clearly.

Final Answer:120