Jimmy and Natalie are selling flower bulbs for a school fundraiser. Customers can buy bags of windflower bulbs and packages of crocus bulbs. Jimmy sold 4 bags of windflower bulbs and 7 packages of crocus bulbs for a total of $90. Natalie sold 4 bags of windflower bulbs and 1 package of crocus bulbs for a total of $30. Find the cost each of one bag of windflower bulbs and one package of crocus bulbs.