Karen is planting 18 bushes and 12 trees in rows. If she wants all the rows to be exactly the same, with no plants left over, what is the greatest number of rows Karen can plant? ? rows

Atruck can be rented from company a $50 a day plus $0.60 per mile. company b charges $20 a day plus $0.80 per mile to rent the same truck. find the number of miles in a day at which the rental costs for company a and company b are the same