Throughput accounting - Revision mock exam

Good evening, Please could you explain how to get the answer to this question: A company makes two products - X and Y - for which the following details are available: X Y Selling price $50 $32 Material $10 $6 Direct labour $20 $15 Assembly time 20 mins 15 mins Maximum demand 1500 units 1000 units The total assembly time is limited to 600 hours.? Using throughput accounting, how many units of Y should be produced? Thank you. Jelena