Question 128
Prove that any finite sum of terms
$$
\frac{1}{abc(a + b + c + 1)}
$$
where $a, b, c$ are positive integers, is smaller than 6.
$$
\frac{1}{abc(a + b + c + 1)}
$$
where $a, b, c$ are positive integers, is smaller than 6.
MathNet 2026 — Part 06 Question 128
Math Olympiad Vault · MathNet 2026 — Part 06