Which type of epithelial tissue allows transportation of substances through a selective permeable surface in the lining of food vessels or lung alveoli?
Rajesh walks 2 km to south, then turns northeast, and walks 3 km. Then he turns south and walks 2 kms. Then he turns west and walks 4 kms. Finally, he turns northwest and walks 5 kms. In which direction is he from his starting point?