A clock takes 9 seconds to strike 4 times. Assuming equal intervals between strikes, how long will it take to strike 12 times at the same rate?

Introduction / Context:
Striking counts involve intervals between strikes. n strikes have (n − 1) intervals. If the interval length is known, time for any other number of strikes scales with interval count.

Given Data / Assumptions:

• 4 strikes → 3 equal intervals → total 9 s.
• Same striking rate for 12 strikes.

Concept / Approach:
Interval length = 9 / 3 = 3 s. For 12 strikes, intervals = 11 → time = 11 * 3.

Step-by-Step Solution:
Time for 12 strikes = 11 * 3 = 33 seconds.

Verification / Alternative check:
Check proportionality with small cases; logic holds.

Why Other Options Are Wrong:
27, 30, 36 assume wrong interval counts or mis-scale the base time.

Common Pitfalls:
Using n instead of (n − 1) intervals.

Final Answer:
33 seconds