If you are asked "If you round 35 to the nearest ten, what do you get?" there is no unique good answer, because there is no one "nearest ten" to 35. Both 30 and 40 are equally close to 35. Sometimes schools teach some kind of rule that governs what to do in an ambiguous situation like this, but those rules are different in different countries. So the GMAT will never test how to round 35 to the nearest ten, because then the GMAT would only be testing where you learned math, and that's not what the GMAT is trying to measure. The GMAT is very careful to avoid using questions that might be culturally biased (that's one of the things they check for when they evaluate experimental questions), so they will never use a question that gives an advantage to test takers who happen to have studied in a national education system that teaches the same 'rounding rule' the GMAT happens to have arbitrarily settled on. So this issue will never matter on a genuine test question.
As for the question in this thread:
kiran120680 wrote:
Amy wrote 320 pages (rounded to nearest tens) in 20 days (rounded to nearest tens). On an average, the number of pages ‘x’ that Amy wrote per day must have been between -
A. 315/25≤x≤325/15
B. 315/15<x<325/25
C. 315/24≤x≤324/15
D. 320/25<x<320/15
E. 315/20<x<325/20
it makes no sense, either grammatically or mathematically. It is clearly an attempt to copy Q192 in OG2018 PS (the "Cindy drove her car..." question) with different numbers and nouns. If anyone wants to see a properly designed question testing these concepts, the
OG question is the one to look at. This question, however, is logically nonsensical. For one thing, we don't know that the quantities must be measured in integers, and we'd need to know that to have any hope of justifying the "OA" of C. But worse still, if C is right, and x is between 315/24 and 324/15, then clearly A is also right, because every number that is between 315/24 and 324/15 is automatically also between 315/25 and 325/15, the range in A, because the range in A completely contains the range in C.
So this question doesn't make any sense, and there's no reason to study it.
Posted from my mobile device _________________
http://www.ianstewartgmat.com