Wang Yong owes the bank $\$8500$. To repay the debt, he paid a fixed amount back to the bank each month. After $12$ months, his remaining debt was $\$6460$.
**How much did Wang Yong pay each month?**
$\qquad$$\$$[[☃ math-keypad 1]]
**How long did it take Wang Yong to pay back his entire debt?**
$\qquad$[[☃ math-keypad 2]] months