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
- (a) 2
- (b) 4 ✓ UPSC's answer
- (c) 5
- (d) 8
Why the answer is (b)
• '256' (red colour chalk) and '254' (white colour chalk) share 2 and 5, which stand for 'colour' and 'chalk'.
• The remaining digit of '256', 6, is 'red'; the remaining digit of '254', 4, is 'white'.
• So 'white' is 4, option (b).
Why the other options are wrong
- (a) 2
- Digit 2 is common to 'red colour chalk' and 'white colour chalk', so it represents either 'colour' or 'chalk', not 'white'.
- (c) 5
- Digit 5 is common to 'red colour chalk' and 'white colour chalk', so it represents either 'colour' or 'chalk', not 'white'.
- (d) 8
- Digit 8 appears in 'green colour flower' and is not present in the code for 'white colour chalk'.
Asked in the CSAT Paper II of the UPSC Civil Services Preliminary Examination 2017, held on 18 June 2017. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.