-1 OR 5*5=26 --

This is ambiguous without knowing the language, but here’s how it plays out in common interpretations.

Facts:

• 55 = 25, so (55 = 26) is false.
• So the expression is essentially "-1 OR false".

Interpretations:

• Logical OR (nonzero is true):
  • In C/C++/Java/Python (where nonzero or nonempty is considered true in a boolean context): true OR false → true.
    • Note: in Python, -1 or False would actually evaluate to -1 (the value), but the boolean result is still true.
• Logical OR that yields 1/0 (C-style ||):
  • -1 || 0 → 1 (true).
• Bitwise OR (|):
  • -1 | 0 → -1 (because -1 is all bits 1 in two’s complement).

Most exam contexts assume “OR” is logical OR with nonzero meaning true, so the answer would be true (or 1). If you tell me the language or the exact convention used in your course, I can tailor the result precisely.