Which one of the following boxes contains the golf ball ?
- (a) F
- (b) E ✓ UPSC's answer
- (c) D
- (d) None of the above
Why the answer is (b)
• Box A is at the extreme right (Position 6), is orange, and contains the tennis ball.
• Box C is fifth from the right (Position 2), is green, and contains the cricket ball.
• Box C is next to Box B, so Box B is at Position 1 or 3. Since Box A is at 6, the positions are 1, 2, 3, 4, 5, 6. C is at 2. B is next to C, so B is at 1 or 3.
• The box with the hockey ball is between the boxes with the golf ball and the volleyball ball. Box B contains volleyball.
• If B is at 1, it cannot be 'between' two other boxes in a linear arrangement of 6 boxes unless we consider the sequence Golf-Hockey-Volleyball or Volleyball-Hockey-Golf. However, 'between' usually implies immediate adjacency in these puzzles or just positional order. Let's look at the constraints: Hockey is not in D or E. Hockey is not in Blue or Yellow.
• Let's determine B's position. If B is at 1, the sequence involving B (Volleyball) and Hockey must be B-H-G or G-H-B. If B is at 1, G-H-B is impossible (B is end). B-H-G would mean B(1), H(2), G(3). But C is at 2. So H cannot be at 2. Thus B cannot be at 1.
• Therefore, Box B is at Position 3. Box C is at Position 2. Box A is at Position 6.
• The hockey ball is between the golf ball and the volleyball ball (Box B). So the sequence is Golf - Hockey - Volleyball (B) or Volleyball (B) - Hockey - Golf.
• Since B is at 3, the hockey ball must be at 2 or 4. But Box C is at 2 and contains Cricket. So Hockey cannot be at 2.
• Therefore, the sequence must be Volleyball (B, Pos 3) - Hockey (Pos 4) - Golf (Pos 5). Or Golf (Pos 2) - Hockey (Pos 3) - Volleyball (Pos 4)? No, B is Volleyball. So B is one end of the 'between' pair. The box with Hockey is between Golf and Volleyball. This means the order is Golf - Hockey - Volleyball OR Volleyball - Hockey - Golf.
• Since B (Volleyball) is at 3, Hockey must be at 2 or 4. Hockey is not in C (Pos 2, Cricket). So Hockey is at 4.
• If Hockey is at 4, and it is between Golf and Volleyball (B at 3), then Golf must be at 5. The order is B(3, Volley) - H(4, Hockey) - G(5, Golf).
• So, Box E (Position 5) contains the Golf ball.
• The key option (b) E follows from this deduction.
Why the other options are wrong
- (a) F
- Box F is at Position 1, which is not adjacent to the Hockey ball at Position 4 in the required sequence.
- (c) D
- Box D is at Position 4, which contains the Hockey ball, not the Golf ball.
- (d) None of the above
- Box E is correctly identified as containing the Golf ball based on the positional constraints.
Asked in the CSAT Paper II of the UPSC Civil Services Preliminary Examination 2016, held on 7 August 2016. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.