Let $a$ be an integer such that $a \equiv 5 \pmod{7}$. Find the value of $a + 1 \pmod{7}$. Express your answer as a residue between $0$ and the modulus.
We have
\(a \equiv 5 \pmod{7}\\ a+1 \equiv 5+1 \pmod7\\ a+1 \equiv 6 \pmod 7\)
Thus, the answer is 6.
Testing numbers like
\(5,12,19,26,33\), they all satisfy the equation we are given.
Thanks! :)