I3.3 The remainder when 392 is divided by a 2-digit positive integer is $b$. If $c$ is the number of such 2-digit positive integers, find the value of $c$.
$$
392-7=385=5 \times 77=5 \times 7 \times 11
$$

Possible 2-digit positive integer $=11,35,55$ or 77
$$
c=4
$$