Concept:
To answer "Does he owe the greatest balance on card B?", we need to determine the ratio or absolute values of A, B, and C.
Step 1: Analyzing Statement (I)
Equation: \( B + C = 3A \).
This provides a relationship between the sum of two cards and the third.
However, we have no information about the relative values of B and C.
Statement (I) is insufficient.
Step 2: Analyzing Statement (II)
Equations:
\( B = \frac{4}{3} A \implies A = \frac{3}{4} B = 0.75 B \)
\( B = \frac{4}{5} C \implies C = \frac{5}{4} B = 1.25 B \)
Comparing the values:
\( A = 0.75 B \)
\( B = 1.00 B \)
\( C = 1.25 B \)
Clearly, \( C > B > A \).
The greatest balance is on card C. We can definitively say "No, B is not the greatest."
Statement (II) is sufficient.
{Statement (II) is sufficient}