Anil, Kunal, Sumit and Samir leave their respective homes at 7:30 a.m. for the school. Anil reaches school at 7:45 a.m., Kunal reaches at 7:40 a.m., Sumit reaches at 7:50 a.m. and Samir reaches at 7:39 a.m. Who reaches earliest to the school and who reaches last respectively?