The non-negative remainder when $7^{36}$ is divided by 5 is:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 1
$7 \equiv 2 \ (\text{mod } 5)$
$7^{36} \equiv 2^{36} \ (\text{mod } 5)$
$2^{4} = 16 \equiv 1 \ (\text{mod } 5)$
$2^{36} = (2^{4})^{9} \equiv 1^{9} \equiv 1 \ (\text{mod } 5)$
$\text{Non-negative remainder} = 1$