Finishing a Logic Grid Puzzle
Part 5 of 5 of How to Solve Logic Grid Puzzles.
All five clues have been read, and the grid still has plenty of empty squares. This is normal. The rest comes from three moves, used over and over.
Move 1: find the last empty square
Look down the turtle column in the top-left grid. $3, $4 and $6 are all crossed out, so the turtle cost $5.
Move 2: reread the clues
Two clues were waiting for exactly this. Clue 4 says the bear cost 2 dollars less than the turtle, so the bear cost $3. Clue 1 says the bear cost 1 dollar less than the monkey, so the monkey cost $4. That leaves $6 for the dog.
Clue 5 was waiting too. Of the $6 animal and the orange animal, one was the monkey and the other was the dog. The dog cost $6, so the monkey was the orange one. The only animal left for red is then the dog.
Move 3: carry a match across
The bear has two circles: it cost $3, and it was gold. So the $3 animal was gold, which is a circle in the top-right grid. The same goes for the other three animals.
Whenever one item has a circle in two grids, the two things it is matched with also match each other.
The answer
| Prices | Animals | Colors |
|---|---|---|
| $3.00 | bear | gold |
| $4.00 | monkey | orange |
| $5.00 | turtle | white |
| $6.00 | dog | red |
X's carry across too
The same idea works for X's. Once you know the bear cost $3, any color ruled out for the bear is ruled out for the $3 animal, and the other way round. In a bigger puzzle this is often what gets you moving again.
If you are stuck
When none of the three moves finds anything, go back through the clues one at a time. A greater-than, either/or or multi-elimination clue that gave you little the first time will often give you more once the grid has filled in around it.