Help with passing ISM v4 exam

Hi I am looking to get help on ways to study and pass the ISM exam. i have taken it 2x and failed. I know it requires extensive studying (800pg training materials given from class) . But can you help with understanding the Storage Systems formulas (# of GB/ Disks  based on RAID type), and Networking protocols (iSCsi, FCoE), Formulas for MTTR/IA. Anything helps as this test covers a wide range of things and every it's different.