Tony spends $\$80$ per month on public transportation. A 10-ride pass costs $\$12.50$, and a single-ride pass costs $\$1.50$. If $g$ represents the number of 10-ride passes Tony buys in a month and $t$ represents the number of single-ride passes Tony buys in a month, which of the following equations best represents the relationship between $g$ and $t$?