2020 CSAT, all questions
UPSC Prelims 2020 · CSAT
Question 20: Logical Reasoning and Mental Ability
If in a particular year 12th January is a Sunday, then which one of the following is correct?
a15th July is a Sunday if the year is a leap year.
b15th July is a Sunday if the year is not a leap year.
c12th July is a Sunday if the year is a leap year.
d12th July is not a Sunday if the year is a leap year.
AnswerUPSC’s answer is (c).
From 12 January to 12 July is 181 days in a normal year and 182 in a leap year (31 + 28 + 31 + 30 + 31 + 30, with 29 for February in a leap year). 182 is exactly 26 weeks, so in a leap year 12 July is also a Sunday. In a normal year 181 leaves a remainder of 6, so 12 July is a Saturday.
Why each option is right or wrong
- (a) In a leap year 15 July is 3 days after a Sunday, a Wednesday.
- (b) In a normal year 12 July is a Saturday, so 15 July is a Tuesday.
- (c) Right: 182 days is whole weeks, so 12 July is a Sunday in a leap year.
- (d) Opposite of (c): it is a Sunday in a leap year.
Answer: UPSC’s key. Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 2020, General Studies Paper II (CSAT), Series A. The paper on upsc.gov.in.