Omega Restaurant received an invoice dated July 22 from Industrial Kitchen Equipment for $3691, with terms 2/10,

Question:

Omega Restaurant received an invoice dated July 22 from Industrial Kitchen Equipment for $3691, with terms 2/10, 1/20, n/45. Omega made payments of $1100 on August 1, $900 on August 10, and $800 on August 31. What amount was still owed on September 1?