31h + 255 = c\nhow many customers are served during a 12 - hour day?\nc = ?

Explanation:

Step1: Substitute h value

Given $h = 12$, substitute into $31h+255 = c$. So we have $31\times12 + 255=c$.

Step2: Calculate multiplication

$31\times12=372$, so the equation becomes $372 + 255=c$.

Step3: Calculate addition

$372+255 = 627$, so $c = 627$.

Answer:

$627$