n represent the hundredths digit in the number shown above.

Question

Consider a Number 3.1n5

n represent the hundredths digit in the number shown above. If the number is rounded to the nearest hundredth, which of the following could be the tenths digit in the rounded number?

A. 0
B. 2
C. 4
D. 5
E. 6

Bunuel · Accepted Answer

Rounding rules

Rounding is simplifying a number to a certain place value. To round the decimal drop the extra decimal places, and if the first dropped digit is 5 or greater, ROUND UP the last digit that you keep. If the first dropped digit is 4 or smaller, ROUND DOWN (keep the same) the last digit that you keep.

Example:
5.3485 rounded to the nearest tenth = 5.3, since the dropped 4 is less than 5.
5.3485 rounded to the nearest hundredth = 5.35, since the dropped 8 is greater than 5.
5.3485 rounded to the nearest thousandth = 5.349, since the dropped 5 is equal to 5.

For more check Number Theory chapter of Math Book: math-number-theory-88376.html

Hope it helps.

P.S. Please read and follow: rules-for-posting-please-read-this-before-posting-133935.html

ConnectTheDots · Answer

3.1n5 - if rounded upto tenth digit, it can either be 3.1 or 3.2 . 
since 1 is not in choice, so 2 is the answer.

30 seconds. strip of the extra information : If the number is rounded to the nearest hundredth

gmatdaynnight · Answer

HI All,

I got this one in 53 seconds, please let me know in case there is any faster way to solve these kinds of questions.

In theis ques we are given the thousandth digit as 5, so the hundreth digit can take any value from 0-9. For the hundreth digit i considered 2 set of values (i) 0, 1, 2, 3 and (ii) 4, 5, 6, 7, 8, 9. Given that the thousandth digit is 5, the undreth digit has to go up by 1, and correspondingly, the tenth digit should also increase by 1 ( provided the hundreth digit is from the 2nd category. Since B was the only one amongst the feasable ans choise, i selected B .

KapTeacherEli · Answer

Very good summary!

Rounding can only do two things to a digit that remains in the number: leave a digit unchanged, or increase a digit by 1 (which can reset a 9 to a zero and increase the NEXT digit).

Since the tenths digit is currently a 1, almost everything else in the Q-stem is irrelevant. The tenths digit can never round to anything other than a 1 or a 2, and so (B) is the only possible answer.

felipelengert · Answer

In my opinion this question is wrong.. If you round the number to the nearst hundredth, the tenth digit will certainly be 1.
But this options is not available..

Am I right?

Bunuel · Answer

No. If n=9, then 3.1n5 rounded to the nearest hundredth would be 3.2.

felipelengert · Answer

Good point... tks Bunuel!

sony1000 · Answer

This question is quite confusing because it is asking the reader to look at the answers provided and n could mistakenly be associated with the answer choices, quite disturbing lol...

Meisme · Answer

The question only mentioned rounding to the hundredths, why would the tenths digit got impacted at all?

pfrojasfellay · Answer

confusing question

bumpbot · Answer

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n represent the hundredths digit in the number shown above.

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