[PHYS 112] - Final Exam Guide - Comprehensive Notes for the exam (75 pages long!)

hi, I found a serway guide with a whole bunch of question andanswers. However, they don't give step by step solutions to theproblems. Simply, the answer. IS anyone familiar with this pdf andknow where I may be able to find the step by step solutions tothose problems?
http://www.scribd.com/doc/18102761/Serway-7th-Chapter-112-Multiple-Choices

Two hockey players collide at an angle of 112 degrees. Each has a mass of 75 kg and travels at a speed of 4.8 m/s before the collision. If they stick together after the collision, what is their final speed?

Note: Please disregard the work done on the graph because it iswrong! And plz show step by steps in details so I can understand it(trying to study for exam ;) Thanks so much!