The value of 3^18 ±od 4 is equal to

The correct answer is Option (3) → 1

Since 3 is one less than 4, \(3 \equiv -1 \pmod 4\). Powers of a congruence keep the congruence:

    \(3^{18} \equiv (-1)^{18} \pmod 4\)
\((-1)^{18} = 1\), since 18 is even

    \(3^{18} \equiv 1 \pmod 4\)

So the remainder when \(3^{18}\) is divided by 4 is 1.