Mrs. Gordon sometimes makes her melon salad for special events. When she made it

a couple months ago, she used 3 pounds of honeydew melon and 7 pounds of

watermelon, which cost her $16. Today, she used 7 pounds of honeydew melon and 4

pounds of watermelon, spending a total of $25 on the melons. Assuming that the

prices of the melons haven't changed, how much does a pound of each type of melon

cost?