Aon-style drills
Aon-style grid deduction (gapChallenge)
Work out the missing shape in a grid where no shape repeats in a row or column, open-ended for 6 minutes
Used by Morgan Stanley (Unverified)
The format
- Time6 minutes on one countdown
- Each grid4 by 4 or 5 by 5, with some shapes, some gaps and one ?
- The ruleNo shape appears twice in any row or column
- GridsNo set number, and a new one after each answer
- Scoring+1 right, −1 wrong
- Have readyA pencil and paper to track your steps, if you like
How to approach it
- Start with the ?'s own row and column
- If that isn't enough, fill a neighbouring gap first
- Some gaps can't be worked out, so solve only what the ? needs
More optionsExtra time, practice, shortcuts
- Untimed practice firstOne untimed practice grid you can repeat
- Keyboard shortcuts
Single-key shortcuts can clash with some screen readers, so switch them off if they get in the way
Format notes
What this drill copies from the published format and how sure we are of each value, checked 22 September 2026
| Parameter | Value | Label |
|---|---|---|
| Total time | 6 minutes on one countdown | OfficialSource 1 for Total timeSource 2 for Total time |
| Grids | No set number: a new one after each answer | OfficialSource for Grids |
| Grid sizesBoth sizes are official; the levels where they change are our choice | 4 by 4 at first, both sizes from level 3 and 5 by 5 from level 5 | OfficialSource for Grid sizes |
| The rule | No shape repeats in any row or column | OfficialSource for The rule |
| Answer tiles | One per shape in use, under the grid | OfficialSource for Answer tiles |
| Notes in empty cellsFilling cells as notes is official; only the ? counting is our reading | Tap an empty cell to try a shape there; only the ? is marked | OfficialSource for Notes in empty cells |
| Gaps you can't work out | Some, on purpose | OfficialSource for Gaps you can't work out |
| Answering | Choose a tile under the grid and the next grid appears | OfficialSource for Answering |
| DifficultyThe provider says grids may get harder; how isn't published, so the steps are our choice, and here grids stop getting harder at level 8 | One level up after a right answer and one down after a wrong one | UnverifiedSource for Difficulty |
| Going backThe provider doesn't describe a way back, so forward only is our reading | Not possible: answer and the next one appears | Unverified |
| Wrong answers | Usually cost points | OfficialSource for Wrong answers |
| ScoringThe size of the deduction is our reading, and there are no blanks as every item needs an answer to go on | +1 for a right answer, −1 for a wrong one | UnverifiedSource for Scoring |
| Before the test | One practice grid you can repeat, then a summary page | OfficialSource 1 for Before the testSource 2 for Before the test |
| PausingEnd test is here for practice only | Not possible, and the test ends itself when time is up | OfficialSource for Pausing |
| Morgan StanleyOne prep site lists it for finance, fund services and operations | A 6-minute grid test in some divisions | UnverifiedSource for Morgan Stanley |
Independent practice in the style of Aon's published format. Not affiliated with or endorsed by Aon