What is the Regular product demand constraint.

Please refer to the information below There may be benefit to using Excel | Solver for this problem set Company X produces two products, Regular (R) and Special (S) Regular product has $125 contribution margin Special product has $200 contribution margin Production capacity limited by available machine hours and labor hours Minimum demand for Regular product is 50 units per month Maximum demand for Special product is 80 units per month Manufacturing labor limited to 1600 hours per month Machine hours limited to 1200 per month Regular product requires 20 labor hours and 10 machine hours Special product requires 30 labor hours and 20 machine hours Management would like to maximize its contribution margin