Use the following information to answer questions 35-37.
The Environmental Club at Forrest Hills High School grows plants in the school's greenhouse. The members of the club sell the plants to raise money for the school, and Sami and Jacque are taking an inventory of the plants. The table below gives the numbers of packs of plants. For example, there are 60 packs of sunflowers with 1 plant per pack, 25 packs of petunias with 4 plants per pack, and 15 packs of tomatoes with 6 plants per pack. All of the packs have been counted except for the 6-plant packs of marigolds.
35. Jacque completes the inventory and later tells Sami that the number of marigold plants is the same as the number of petunia plants. How many 6-plant packs of marigolds are in the greenhouse?