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CUET · MATHS · PYQ PAPER 2025

The least non-negative remainder, when \(5^{61}\) is divided by 7 , is

  1. A 6
  2. B 4
  3. C 5
  4. D 2
Verified Solution

Answer & Solution

Correct Answer

(C) 5

Step-by-step Solution

Detailed explanation

\(5^6 \equiv 1 \pmod{7}\) \(5^{61} = 5^{6 \times 10 + 1} = (5^6)^{10} \cdot 5^1 \pmod{7}\) \(5^{61} \equiv (1)^{10} \cdot 5 \pmod{7}\) \(5^{61} \equiv 5 \pmod{7}\)