Q16. Grids
TITA · +3 / 0
How many houses are vacant in Block XX? (in numerial value)
Correct Answer
3
Step-by-step solution
📌 Core Concept
Work out the road adjacency of each house, then use the price clues to fix which houses are occupied. The maximum price of 24 in Block XX is the key.
🔢 Step-by-Step Solution
1
Road adjacency values: A1, B1 and E1 are 0. C1, D1 and every house in Row-2 are 1, except C2 and D2, which touch both roads and have 2. F1 is 0 and F2 is 1.
2
A quoted price is . In Block XX, a price of 24 needs base 10 with . The only solution is , . A base of 12 would need , which has no valid solution.
3
A house with and three occupied neighbours must be in Row-2 with neighbours on both sides and above. That house is B2, with A2, C2 and B1 all occupied and B2 itself vacant.
4
Clue 2 says Row-1 has only one occupied house in each block. B1 is that house, so A1 and C1 are vacant.
5
Vacant houses in Block XX: A1, C1 and B2.
Quick Check
C1 costs , or 23 with parking. A1 costs at most 18. Both are below 24, so the maximum of 24 comes only from B2.
Correct Answer: 3