Pounds is a weight not a mass. A pound on earth relies on gravity of 32 ft/s^2 so the wording in this problem is consistent. For what it’s worth I came up with the exact same solution before checking the comments. Also, I’m sure someone straightened out the pound dilemma further down, but I’m too lazy to read further.

Pretty much anything by Christopher Moore. Practical Demonkeeping or Bloodsucking Fiends are great places to start though.