UPSC Prelims 2016 CSAT Paper II · Q7 of 79 Logical Reasoning easy

A ate grapes and pineapple; B ate grapes and oranges; C ate oranges, pineapple and apple; D ate grapes, apple and pineapple. After taking fruits, B and C fell sick. In the light of the above facts, it can be said that the cause of sickness was :

  1. (a) Apple
  2. (b) Pineapple
  3. (c) Grapes
  4. (d) Oranges ✓ UPSC's answer

Why the answer is (d)

• Identify the common fruits consumed by the sick individuals, B and C: B ate grapes and oranges, while C ate oranges, pineapple, and apple.

• The only fruit present in both B's and C's consumption lists is oranges.

• Check if other fruits could be the cause: Grapes were eaten by A (who did not fall sick), ruling out grapes.

• Pineapple was eaten by A (who did not fall sick), ruling out pineapple.

• Apple was eaten by A (who did not fall sick), ruling out apple.

• Since oranges are the only fruit common to both sick individuals and not consumed by the healthy individual A, oranges are the cause of sickness.

Why the other options are wrong

(a) Apple
Apple was eaten by A, who did not fall sick, so it cannot be the cause.
(b) Pineapple
Pineapple was eaten by A, who did not fall sick, so it cannot be the cause.
(c) Grapes
Grapes were eaten by A, who did not fall sick, so it cannot be the cause.

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.

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.

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