Easy — logic-grid deduction puzzle
Spilled ink has blotted out the ledger page where Kirsten, Lucius, Mirabel and Norbert wrote down their morning calls.
The little switchroom had only just come through its morning rush. Four lines ran in a row along the board, from the first to the fourth. Kirsten, Lucius, Mirabel and Norbert had each worked one of them and taken one call apiece. Then somebody's elbow caught the ink bottle. The ink ran right across the ledger where every call gets written down, and the whole morning's page became one big black blot. The plugs were already back in their holes, so the board couldn't help either. Now the four of them have to put the morning back together from what they remember.
Read the clues, rule out what cannot be, and prove what must be. Every GRIDIGMA puzzle is verified by a solver that shows the reasoning behind each step, so a solution is never a guess.
Logic grid puzzles: how to solve them, with a worked example