UP High Court RO / ARO 10 Dec 2021 Shift 1

Three different positions of the same dice are shown below. Which number is on the face of the dice opposite the face showing the number 1 ? Diagram Required

Verified Answer
A. (1) 3
B. (2) 4
C. (3) 6
D. (4) 2

Explanation:

To find the number opposite to 1, we can use the rules of dice or compare adjacent faces. \nLet's list the adjacent faces for each number from the given three positions: \nFrom Dice 1 (faces: 3, 5, 1): - 1 is adjacent to 3 and 5. - 3 is adjacent to 1 and 5. - 5 is adjacent to 1 and 3. \nFrom Dice 2 (faces: 6, 5, 4): - 5 is adjacent to 6 and 4. - 6 is adjacent to 5 and 4. - 4 is adjacent to 5 and 6. \nFrom Dice 3 (faces: 3, 4, 2): - 3 is adjacent to 4 and 2. - 4 is adjacent to 3 and 2. - 2 is adjacent to 3 and 4. \nNow, let's find all numbers adjacent to 1:\nFrom Dice 1, 1 is adjacent to 3 and 5. \nLet's find all numbers adjacent to 3:\nFrom Dice 1, 3 is adjacent to 1 and 5.\nFrom Dice 3, 3 is adjacent to 4 and 2.\nSo, 3 is adjacent to $\{1, 2, 4, 5\}$. The only number remaining from 1-6 is 6. Therefore, 3 is opposite to 6. \nLet's find all numbers adjacent to 5:\nFrom Dice 1, 5 is adjacent to 1 and 3.\nFrom Dice 2, 5 is adjacent to 6 and 4.\nSo, 5 is adjacent to $\{1, 3, 4, 6\}$. The only number remaining from 1-6 is 2. Therefore, 5 is opposite to 2. \nWe have established two pairs of opposite faces: - 3 is opposite 6. - 5 is opposite 2. \nThe remaining numbers are 1 and 4. Therefore, 1 must be opposite to 4. \nAlternatively, using the 'two common faces' rule:\nCompare Dice 1 (3, 5, 1) and Dice 3 (3, 4, 2).\nCommon face: 3.\nClockwise from 3 in Dice 1: 5, then 1.\nClockwise from 3 in Dice 3: 2, then 4.\nThus, 5 is opposite 2, and 1 is opposite 4. \nAnalyzing the options: (1) 3: This is incorrect. From Dice 1, 1 and 3 are adjacent, so they cannot be opposite. (2) 4: This is correct. Our derivation shows 1 is opposite 4. (3) 6: This is incorrect. 6 is opposite 3. (4) 2: This is incorrect. 2 is opposite 5. \nThe logically derived answer is 4. Please note that the provided answer key in the document indicates option (1) 3 as correct, which contradicts this derivation. It is impossible for 1 to be opposite 3, as they are shown on adjacent faces in the first dice image.