Answer: 2000
Explanation: Subject: Math — basic counting / combinatorics. Concept used: Fundamental Counting Principle (multiply independent choices).
Steps:
- The first two digits are fixed to be either 53 or 54 → 2 choices.
- Each of the remaining three digits can be 0–9 independently → \(10^3 = 1000\) choices.
- Total possible ZIP codes = \(2 \times 1000 = 2000\).
(Assumption: all 5-digit combinations with those starting digits, including endings like 000, are allowed.)