In a certain code, '256' means 'red colour chalk', '589' means 'green colour flower' and '254' means 'white colour chalk'. The digit in the code that indicates 'white' is

To solve this elegantly, I will focus strictly on the target word 'white'. \n\n1. **Locate the target:** 'White' appears **only** in the third statement: '254' means 'white colour chalk'.\n\n2. **Apply Logic of Uniqueness:** Since 'white' is unique to this statement (it doesn't appear in the first two), its code must be a digit that is **unique** to '254'. This aligns with the 'Uniqueness' concept seen in 2016 PYQs [25], [33].\n\n3. **Eliminate Common Elements:** Now I check the digits in '254' against the others:\n * **Digit 5:** It appears in '256' and '589'. Since 'white' isn't in those sentences, '5' cannot be 'white'. (It likely maps to the common word 'colour'). This uses the 'Set Intersection' logic [9].\n * **Digit 2:** It appears in '256'. Since 'white' isn't there, '2' cannot be 'white'.\n * **Digit 4:** It appears **only** in '254'. This matches the behavior of the word 'white'.\n\n4. **Conclusion:** By process of elimination [52], '4' must represent 'white'.