Marc's home is 10 blocks from the library. after school, marc walked from his house to his friend's house, which is in the opposite direction of the library, at a rate of 1 block every 2 minutes. it took marc 4 minutes to walk to his friend's house. after he met up with his friend, he immediately began to walk towards the library at a rate of 1 block every 1 minute. plot the points on the grid that represent when marc began his walk, when marc met his friend, and then marc arrived at the library.