A local salsa company makes two types of salsa, tomato and corn. Each batch of tomato salsa takes 2 hours to prepare and 4 hours to package. Each batch of corn salsa takes 2.5 hours to prepare and 3 hours to package. There are 4 preparation workers and 7 packaging workers in the company. Each of them works 40 hours per week. in order to maximize productivity, how many batches of salsa should be made if the company owner wants 20 batches of corn salsa. 2t+2.5c ≤160 and 4t + 3c ≤280​