UPSC Prelims 2007 · General Studies
Question 14: Basic Numeracy
Consider the following statements:
- 1.The series of international paper sizes is based on A0 size whose area is 0.5 m² (approx).
- 2.The area of A4 size paper is 1⁄8th of the A0 size paper.
Which of the statements given above is/are correct?
AnswerThe answer is (d).
The A-series paper sizes are built on A0, whose area is 1 square metre (841 mm by 1189 mm), not 0.5. Each step down, such as A1 from A0, halves the area by cutting the long side in two. So A1 is one half, A2 one quarter, A3 one eighth and A4 one sixteenth of A0. Both statements are wrong.
- 1. A0 has an area of 1 m2, not 0.5 m2.
- 2. A4 is 1/16 of A0, since each size halves the area.
How you could have got this
- If you were sure statement 1 is not correct, (a) and (c) go: each of them includes 1.
What you needed to know: A0 has an area of 1 m2, not 0.5 m2.
- Then, if you were sure statement 2 is not correct, (b) goes: it includes 2.
What you needed to know: A4 is 1/16 of A0, since each size halves the area.
Only (d) is left. This one needs every statement.
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) Statement 1 is wrong; A0 has an area of 1 m2.
- (b) Statement 2 is wrong; A4 is 1/16 of A0, not 1/8.
- (c) Both statements are wrong.
- (d) Correct: A0 is 1 m2 and A4 is 1/16 of it, so neither holds.
Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 2007, General Studies. UPSC's own paper isn't online; the words are from a published compilation. The paper on upsc.gov.in.