2019 CSAT, all questions
UPSC Prelims 2019 · CSAT
Question 18: Basic Numeracy
In 2002, Meenu's age was one-third of the age of Meera, whereas in 2010, Meenu's age was half the age of Meera. What is Meenu's year of birth ?
a1992
b1994
c1996
d1998
AnswerUPSC’s answer is (b).
Let Meenu be m years old in 2002, so Meera is 3m. Eight years later Meenu is m + 8 and Meera is 3m + 8, and Meenu is half of Meera: 2(m + 8) = 3m + 8, so m = 8. Meenu was 8 in 2002, so she was born in 1994. Check: in 2010 she is 16 and Meera is 32.
Why each option is right or wrong
- (a) Wrong: 1992 gives ages 10 and 30 in 2002, which fail the 2010 condition.
- (b) Right: ages 8 and 24 in 2002, then 16 and 32 in 2010.
- (c) Wrong: 1996 gives ages 6 and 18 in 2002, which fail in 2010.
- (d) Wrong: 1998 gives ages 4 and 12 in 2002, which fail in 2010.
Answer: UPSC’s key. Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 2019, General Studies Paper II (CSAT), Series A. The paper on upsc.gov.in.