UPSC Prelims 2021 · CSAT

Question 47: Data Interpretation

Consider two Statements and a Question :

Statement-1The last day of the month is a Wednesday.
Statement-2The third Saturday of the month was the seventeenth day.
QuestionWhat day is the fourteenth of the given month ?

Which one of the following is correct in respect of the Statements and the Question ?

aStatement-1 alone is sufficient to answer the Question

bStatement-2 alone is sufficient to answer the Question

cBoth Statement-1 and Statement-2 are required to answer the Question

dNeither Statement-1 alone nor Statement-2 alone is sufficient to answer the Question

AnswerUPSC’s answer is (b).

Statement 2: the third Saturday is the 17th, so Saturdays fall on the 3rd, 10th, 17th, 24th and 31st, and the 14th is three days before a Saturday: a Wednesday. Statement 1 says the last day is a Wednesday, but the month's length is unknown (28 to 31 days), so the 14th cannot be fixed: a 30-day month and a 31-day month ending on Wednesday give different weekdays for the 14th. Statement 2 alone is sufficient. Remember: fix the weekday of one date first, then count back or forward.

Why each option is right or wrong

(a) Statement 1 alone is not enough: the length of the month is unknown, so the 14th's weekday is not fixed.
(b) Right: the 17th is a Saturday, so the 14th, three days earlier, is a Wednesday.
(c) Statement 2 alone settles it, so Statement 1 is not required.
(d) Statement 2 alone is sufficient, so this fails.

Answer: UPSC’s key. Explanation: written by UPSC Grade, not by UPSC.

Practise this paper timedPrevious question Next question

Source: UPSC, Civil Services (Preliminary) Examination 2021, General Studies Paper II (CSAT), Series A. The paper on upsc.gov.in.