Question 4
Solve the following Binairo puzzles:

A Binairo (or Takuzu) puzzle is a logic grid game played on a grid (here, ). We represent black dashes as (or ) and red vertical lines as (or ).
- Equal Count: Each row and column must contain an equal number of both symbols (exactly three s and three s in a grid).
- No Triples: No more than two identical symbols can be adjacent horizontally or vertically (no or ).
- Uniqueness: Each row and column configuration must be unique and valid.
(i) Solve Grid 1
Step 1 · Fill Grid 1 using Binairo Rules
Let black dashes be and red vertical lines be .
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Cells and are cell .
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Cells and are cell .
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Balancing Row 1 (needs three s and three s) cell .
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Column 3 has at , , and (already three s) .
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Column 2 has at and .
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Row 3 now has three s at .
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In Row 2, and are and .
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In Column 1, and are . Column 1 now has three s .
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In Row 6, and are .
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In Row 4, and are .
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Column 2 now has three s .
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Column 4 has three s .
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In Row 4, and are . Balancing Row 4 gives .
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In Column 5, and are and . Balancing Column 5 gives .
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Balancing remaining rows:
- Row 2:
- Row 5:
- Row 6:
(i)
(ii) Solve Grid 2
Step 1 · Fill Grid 2 using Binairo Rules
Let black dashes be and red vertical lines be .
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Column 1 has and .
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Row 3 already contains three s at .
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Column 3 has three s at .
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In Row 1, and are .
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In Row 2, and are .
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In Row 4, and are .
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In Row 5, and are .
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In Row 6, and are .
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Column 5 has .
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Row 5 has three s and .
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Column 1 has , giving .
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Column 2 has , giving .
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Balancing remaining cells:
- Row 4:
- Column 4:
- Row 1:
- Column 6:
- Row 2:
(ii)
(iii) Solve Grid 3
Step 1 · Fill Grid 3 using Binairo Rules
Let black dashes be and red vertical lines be .
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In Column 6, and are .
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In Row 1, .
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In Row 3, .
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Column 1 has .
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In Row 2, .
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In Column 5, .
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In Row 3, . Balancing Row 3 gives .
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Column 3 already contains three s .
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In Column 4, to avoid violating Row 2 rules, . Column 4 now has three s .
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Row 2 has three s .
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Column 2 has . Balancing gives .
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Balancing remaining rows:
- Row 1:
- Row 4:
- Row 5:
- Row 6:
(iii)
- Consecutive Symbols Violation: Placing three identical symbols consecutively in any row or column (e.g., or is not permitted).
- Incorrect Symbol Count: Exceeding the maximum allowed count of 3 dashes () or 3 vertical lines () in any row or column.
- Overlooking Between-Pairs Rule: Failing to notice that two identical symbols with a one-cell gap (e.g., ) must have the opposite symbol between them ().
More questions in A
Take your favourite dish. Find out all the ingredients and their respective quantities needed to make the dish for your family. Suppose you are celebrating a festival and you want to invite 15 guests. Find out the quantities of the ingredients required to cook the same dish for them.
Go to the market and collect the prices of different sizes of shampoo containers of the same shampoo and create a table like the one given below. See if the volume of shampoo is proportional to the price.
Activity 3: Form a pair. Collect 12 countable objects or counters (it can be coins, seeds, or pebbles). Now, share them between the two of you in different ways.
Solve the following Binairo puzzles: