I googled it for Tennessee and every time got a different test. The actual one (I think) was not hard but the others were difficult. I hope it's the easy one.
Go to the truckstop buy a current Year Hazmat guide. It should be in either a orange or yellow overall appearance a little bigger than a walkman. In it should contain the entire current USA and UN 4 digit format plus specific actions to take for each. That book will be riding with your Green FMCSA DOT regulations book among others.