JB Co makes two products, the JA and the BE. The JA requires 12 minutes of labour time per unit and 20 kgs of material. The BE requires 15 minutes of labour time per unit and 9 kgs of material. Each month 60 labour hours are available and 380 kgs of material. Government restrictions are such that the maximum possible monthly production volume of the JA is 80 units.

The marketing strategy is such that for every JA that is sold, at least two BEs must be sold. The contribution per unit of JA is $45 while the contribution per unit of BE is $57. If linear programming is to be used to determine the contribution-maximising production plan, and if x represents the number of product JA produced and y represents the number of product BE produced, which of the following correctly describe constraints?