UPSC Prelims 2009 · General Studies
Question 97: Logical Reasoning and Mental Ability
How many letters of the English alphabet (capitals) appear same when looked at in a mirror?
AnswerThe answer is (c).
A capital letter looks the same in a mirror (reflected left-right) if it is symmetric about a vertical line. The letters are A, H, I, M, O, T, U, V, W, X and Y: 11 letters. Letters such as B, C, D and E are symmetric only about a horizontal line, so a vertical mirror reverses them.
How you could have got this
No shortcut here: in a “how many” question, ruling out options doesn’t help. Every statement has to be judged.
This follows an unofficial answer: UPSC has not published its key for this year, and if that answer is wrong, so is this path.
Which options go is worked out from UPSC’s key and the options, not by a model.
Why each option is right or wrong
- (a) 9 undercounts the letters.
- (b) 10 undercounts the letters.
- (c) Right: A, H, I, M, O, T, U, V, W, X, Y make 11.
- (d) 12 overcounts.
Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 2009, General Studies. UPSC's own paper isn't online; the words are from a published compilation. The paper on upsc.gov.in.