UPSC Prelims 2019 CSAT Paper II · Q76 of 79 Comprehension medium

Passage

Directions for the following 3 (three) items : Read the following information and answer the three items that follow : Six students A, B, C, D, E and F appeared in several tests. Either C or F scores the highest. Whenever C scores the highest, then E scores the least. Whenever F scores the highest, B scores the least. In all the tests they got different marks; D scores higher than A, but they are close competitors; A scores higher than B; C scores higher than A.

If F stands second in the ranking, then the position of B is

  1. (a) Third
  2. (b) Fourth
  3. (c) Fifth ✓ UPSC's answer
  4. (d) Sixth

Why the answer is (c)

• The condition 'Either C or F scores the highest' implies that if F is not the highest, C must be the highest.

• Since F is stated to stand second, C must be the highest (1st position).

• The rule 'Whenever C scores the highest, then E scores the least' places E in the 6th position.

• The ranking constraints are: C > A > B and D > A. This means A is higher than B, and both C and D are higher than A.

• Therefore, the students ranked higher than B are C, D, and A. Since F is 2nd, the top four positions are occupied by C, F, D, and A in some order, but all are above B.

• With C (1st), F (2nd), and E (6th) fixed, and D and A both ranking higher than B, B must be in the 5th position, with D and A occupying the 3rd and 4th positions.

Why the other options are wrong

(a) Third
B cannot be third because both D and A score higher than B, and C and F are already in the top two positions, leaving no room for B to be third.
(b) Fourth
B cannot be fourth because D and A both score higher than B, meaning at least three students (C, D, A) plus F are above B, pushing B to fifth.
(d) Sixth
B cannot be sixth because the condition states that when C scores highest, E scores the least, so E occupies the sixth position.

Asked in the CSAT Paper II of the UPSC Civil Services Preliminary Examination 2019, held on 2 June 2019. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.

Reading the answer is not the same as getting it right under a clock. Practise this question with UPSC's negative marking, and anything you miss goes into an error notebook until you get it right twice.

Practise this paper free