Suzie loves to chew fruit-flavored gum. She bought four packs of gum the last time she was at the store. She got two packs of her favorite flavor, strawberry. She paid $2 for a pack of grape gum that she also liked. She wanted to try something new, so she paid half as much for a small pack of green apple gum. If she paid $7 in all, how many dollars did each pack of strawberry gum cost?