Sunnybrook Farms is a local grocery store that is currently open only Monday through Saturday.

Sunnybrook is considering opening on Sundays. The annual incremental costs of Sunday openings are estimated at $24,960. Sunnybrook Farms’ gross margin on sales is 20 percent. Sunnybrook estimates that 60 percent of its potential Sunday sales to customers are now made on other days.

What one-day volume of Sunday sales would be necessary for Sunnybrook Farms to attain the same weekly operating income as in the current six-day week?