Answer:
Hydrophytes are defined as the plants that grow in aquatic environment.
Xylem and phloem are part of transport system in plants. Water and minerals from roots to leaves are carried by Xylem and sugar and other organic nutrients are carried by Phloem.
Hydrophytes grow in water, so have access to abundant water. It helps water to diffuse easily in hydrophytes and hence require less number of xylem for water transport.
So, number of xylem are less than the number of phloem in hydrophytes plant.