A biologist caught and tagged 17 grey herons around a lake. She released these birds after being tagged. She returned to the same lake six months later and caught 26 grey herons. The biologist found 2 of these 26 herons had been tagged. Let the numbers of caught and tagged herons on the first trip be set T and the set C be the numbers of herons caught six months later. Let N be the total number of grey herons around this lake. Represent the information above with a labelled Venn diagram. Explain why set T and set C are independent. E Find the value of N