Suppose that we have a set of activities to schedule among a large number of lecture halls, where any activity can take place in any lecture hall. We wish to schedule all the activities using as few lecture halls as possible. Give an efficient greedy algorithm to determine which activity should use which lecture hall.

1. which of the following statements are true about routers and routing on the internet. choose two answers. a. protocols ensure that a single path between two computers is established before sending packets over it. b. routers are hierarchical and the "root" router is responsible for communicating to sub-routers the best paths for them to route internet traffic. c. a packet traveling between two computers on the internet may be rerouted many times along the way or even lost or "dropped". d. routers act independently and route packets as they see fit.