Classification (number pairs – powers): Three pairs follow the pattern second number = first number^3; one pair violates this cube relation. Identify the odd pair.

Introduction / Context:
Numeric classification often uses exponent relations, such as squares and cubes. In this set, the intended relation is second = first^3. Identifying the pair that breaks this rule requires quick recognition of small powers and comfort with mental arithmetic under time pressure.

Given Data / Assumptions:

• Pairs: 2-8, 3-27, 4-32, 5-125.
• We interpret the dash as an ordered pair (a, b) and test whether b = a^3.
• Recall cubes: 2^3 = 8, 3^3 = 27, 4^3 = 64, 5^3 = 125.

Concept / Approach:
Compute cubes of 2, 3, 4, and 5. Compare against the second number of each pair. Any mismatch identifies the odd pair. This is a straightforward recognition task that benefits from memorizing cubes up to at least 10 for speed.

Step-by-Step Solution:

Verification / Alternative check:
Note that 32 is a power of 2 (2^5), which can distract solvers who lean on recognition of common powers without checking the base. Confirm by direct multiplication for 4^3: 4*4*4 = 16*4 = 64.

Why Other Options Are Wrong:

Common Pitfalls:
Confusing powers of 2 with cubes of other integers. Always compute the exact power relation defined by the pattern rather than relying on familiarity with a single number like 32.

Final Answer:
4-32