Question 1143922
<br>
K divided by 4 leaves remainder 1 --> k = 1, mod 4.<br>
Then by the simple rules of modular arithmetic,<br>
3k = 3*1 = 3, mod 4
3k-1 = 3-2 = 2, mod 4<br>
So 3k-1 leaves remainder 2 when divided by 4.