Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized for You

we will pick new questions that match your level based on your Timer History

Track Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

It appears that you are browsing the GMAT Club forum unregistered!

Signing up is free, quick, and confidential.
Join other 500,000 members and get the full benefits of GMAT Club

Registration gives you:

Tests

Take 11 tests and quizzes from GMAT Club and leading GMAT prep companies such as Manhattan GMAT,
Knewton, and others. All are free for GMAT Club members.

Applicant Stats

View detailed applicant stats such as GPA, GMAT score, work experience, location, application
status, and more

Books/Downloads

Download thousands of study notes,
question collections, GMAT Club’s
Grammar and Math books.
All are free!

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

In the decimal, 2.4d7, d represents a digit from 0-9. If [#permalink]

Show Tags

09 Dec 2010, 22:01

1

This post was BOOKMARKED

00:00

A

B

C

D

E

Difficulty:

(N/A)

Question Stats:

100% (01:21) correct
0% (00:00) wrong based on 8 sessions

HideShow timer Statistics

In the decimal, 2.4d7, d represents a digit from 0-9. If the value of the decimal rounded to the nearest tenth is less than 2.5, what are the possible values of d?

Hi ppl..I always get confused about rounding the digit Questions in PS..

Can some one explain me the above Q

Thanks in advance

Last edited by Bunuel on 09 Feb 2012, 07:29, edited 1 time in total.

Hi ppl..I always get confused about rounding the digit Questions in PS..

Can some one explain me the below Q

In the decimal, 2.4d7, d represents a digit from 0-9. If the value of the decimal rounded to the nearest tenth is less than 2.5, what are the possible values of d?

Thanks in advance

REMEBER: In XYZ.abc Z - Units digit y - tens x - hundreds

a - Tenths b - hundredths c - thousandths

ROUNDING concept

Important: THE ROUNDING SHUD TAKE PLACE FROM RIGHT TO LEFT

if the above # is getting rounded to Thenth (a), then the value of "a" depends on the value of "b" (the hundredths place) in the below way.

\(a ==> a+1 , if b>=5\) \(a ==> a , if b<5\)

Original qtn

given # is \(2.4d7\) (as per the above concept, the tenths place value depends upon the value in hundredths place i.e. d)

and as given the resultant # is < 2.5 ==> 2.4 (after rounding to tehnths) so for the 4 (in the tenths place) not to be changed d has to be < 5 ==> d has to be < 5 ==> posiible values for d are \(0,1,2,3, and 4\)

Regards, Murali Kudos?

Last edited by muralimba on 10 Dec 2010, 00:11, edited 1 time in total.

Hi ppl..I always get confused about rounding the digit Questions in PS..

Can some one explain me the below Q

In the decimal, 2.4d7, d represents a digit from 0-9. If the value of the decimal rounded to the nearest tenth is less than 2.5, what are the possible values of d?

Thanks in advance

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.

BACK TO THE ORIGINAL QUESTION: In the decimal, 2.4d7, d represents a digit from 0-9. If the value of the decimal rounded to the nearest tenth is less than 2.5, what are the possible values of d?

So, in order 2.4d7 rounded to the nearest tenth to be less than 2.5, d must be less than 5: 0, 1, 2, 3, or 4. In this case 2.4d7 rounded to the nearest tenth will be 2.4 which is less than 2.5.

Thanks for the explanations Muralimba,mypatpat and Bunnel…

I was under the impression that if d = 4 then

2.447 rounded to nearest tenth is (I was coming from right most digit rounding each preceding digit) 2.45 (since 7>5) 2.5 (since 5=5)

Hence I thght d=4 is also an invalid option…

But now I understand that whenever a digit is rounded we should consider only the digit to the right of our digit .We shall not be worrying about the rest of the digits.

Bunuel,I disagree with u .in case 4372.25 rounded tenth digit(decimal). in these type of problems we have 2 case 1-If the preceding digit(2) is odd and hundred digit is equal to 5. then we increase tenth digit by 1. and n.m. become 4372.3 2-If the preceding digit is even ( in this case),then we left the n.m. unchanged and n.m. become 4372.2 hope you got my point

Bunuel,I disagree with u .in case 4372.25 rounded tenth digit(decimal). in these type of problems we have 2 case 1-If the preceding digit(2) is odd and hundred digit is equal to 5. then we increase tenth digit by 1. and n.m. become 4372.3 2-If the preceding digit is even ( in this case),then we left the n.m. unchanged and n.m. become 4372.2 hope you got my point

The above is not correct for GMAT. Anyway number x.25 rounded to the nearest tenth is x.3.

Again, check 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.

BACK TO THE ORIGINAL QUESTION: In the decimal, 2.4d7, d represents a digit from 0-9. If the value of the decimal rounded to the nearest tenth is less than 2.5, what are the possible values of d?

So, in order 2.4d7 rounded to the nearest tenth to be less than 2.5, d must be less than 5: 0, 1, 2, 3, or 4. In this case 2.4d7 rounded to the nearest tenth will be 2.4 which is less than 2.5.

I am saying 4327.254 ----will be 4327.2 in tenth decimal place. and 4327.354 will be 4327.4 in tenth decimal place value will depend what is coming before 5.It's true. I agree with you.Except in this case. usually -above 5 we increase the n.m.by 1 in decimal digit and below 5 we unchanged the digit. such as 4327.567--- 4327.6 and 4327.435---4327.4 in rounding tenth in decimal digit

I am saying 4327.254 ----will be 4327.2 in tenth decimal place. and 4327.354 will be 4327.4 in tenth decimal place value will depend what is coming before 5.It's true. I agree with you.Except in this case. usually -above 5 we increase the n.m.by 1 in decimal digit and below 5 we unchanged the digit. such as 4327.567--- 4327.6 and 4327.435---4327.4 in rounding tenth in decimal digit

Please read carefully:

For GMAT if the first dropped digit is 5 or more you ROUND UP the last digit that you keep and if the first dropped digit is less than 5 you KEEP THE SAME the last digit that you keep.

4327.254 rounded to the nearest tenth will be 4327.3 since the dropped 5 is equal to 5; 4327.354 rounded to the nearest tenth will be 4327.4 since the dropped 5 is equal to 5.
_________________

Same here...I was thinking exactly the same...thanks for the explanation

krishireddy wrote:

Thanks for the explanations Muralimba,mypatpat and Bunnel…

I was under the impression that if d = 4 then

2.447 rounded to nearest tenth is (I was coming from right most digit rounding each preceding digit) 2.45 (since 7>5) 2.5 (since 5=5)

Hence I thght d=4 is also an invalid option…

But now I understand that whenever a digit is rounded we should consider only the digit to the right of our digit .We shall not be worrying about the rest of the digits.

For GMAT if the first dropped digit is 5 or more you ROUND UP the last digit that you keep and if the first dropped digit is less than 5 you KEEP THE SAME the last digit that you keep..

Hi Bunuel, where did you get the statement above ? OG10, 11, or 12? I am trying to look for it. Here is what I found from a math website, please read Rule Three carefully:

Rule One. Determine what your rounding digit is and look to the right side of it. If the digit is 0, 1, 2, 3, or 4 do not change the rounding digit. All digits that are on the right hand side of the requested rounding digit will become 0.

Rule Two. Determine what your rounding digit is and look to the right of it. If the digit is 5, 6, 7, 8, or 9, your rounding digit rounds up by one number. All digits that are on the right hand side of the requested rounding digit will become 0.

Rounding with decimals: When rounding numbers involving decimals, there are 2 rules to remember:

Rule One Determine what your rounding digit is and look to the right side of it. If that digit is 4, 3, 2, or 1, simply drop all digits to the right of it.

Rule Two Determine what your rounding digit is and look to the right side of it. If that digit is 5, 6, 7, 8, or 9 add one to the rounding digit and drop all digits to the right of it.

Rule Three: Some teachers prefer this method:

This rule provides more accuracy and is sometimes referred to as the 'Banker's Rule'. When the first digit dropped is 5 and there are no digits following or the digits following are zeros, make the preceding digit even (i.e. round off to the nearest even digit). E.g., 2.315 and 2.325 are both 2.32 when rounded off to the nearest hundredth. Note: The rationale for the third rule is that approximately half of the time the number will be rounded up and the other half of the time it will be rounded down.

For GMAT if the first dropped digit is 5 or more you ROUND UP the last digit that you keep and if the first dropped digit is less than 5 you KEEP THE SAME the last digit that you keep..

Hi Bunuel, where did you get the statement above ? OG10, 11, or 12? I am trying to look for it. Here is what I found from a math website, please read Rule Three carefully:

Rule One. Determine what your rounding digit is and look to the right side of it. If the digit is 0, 1, 2, 3, or 4 do not change the rounding digit. All digits that are on the right hand side of the requested rounding digit will become 0.

Rule Two. Determine what your rounding digit is and look to the right of it. If the digit is 5, 6, 7, 8, or 9, your rounding digit rounds up by one number. All digits that are on the right hand side of the requested rounding digit will become 0.

Rounding with decimals: When rounding numbers involving decimals, there are 2 rules to remember:

Rule One Determine what your rounding digit is and look to the right side of it. If that digit is 4, 3, 2, or 1, simply drop all digits to the right of it.

Rule Two Determine what your rounding digit is and look to the right side of it. If that digit is 5, 6, 7, 8, or 9 add one to the rounding digit and drop all digits to the right of it.

Rule Three: Some teachers prefer this method:

This rule provides more accuracy and is sometimes referred to as the 'Banker's Rule'. When the first digit dropped is 5 and there are no digits following or the digits following are zeros, make the preceding digit even (i.e. round off to the nearest even digit). E.g., 2.315 and 2.325 are both 2.32 when rounded off to the nearest hundredth. Note: The rationale for the third rule is that approximately half of the time the number will be rounded up and the other half of the time it will be rounded down.

The part in red is correct.

And again: For GMAT if the first dropped digit is 5 or more you ROUND UP the last digit that you keep and if the first dropped digit is less than 5 you KEEP THE SAME the last digit that you keep.

Banker's rounding (Round half to even) is one of them many tie breaking rules that can be used in case of .5 They are Round half to odd, Round up, Round down, Round towards 0, Round away from 0 etc etc etc (Check http://en.wikipedia.org/wiki/Rounding for explanation of each method.)

As Bunuel mentioned, GMAT uses Round Up by default. (Inferred from the solution they provided for OG12, Data Sufficiency, Q64, Page 309... When d is rounded to the nearest tenth, the result is 0.5. The value of d could range from 0.45 to 0.54. 0.45 is made 0.5 i.e. rounding up is used, not banker's rounding)

Note: Banker's rounding is more accurate since it doesn't have the upward bias but we have to use what GMAT uses.
_________________

Re: In the decimal, 2.4d7, d represents a digit from 0-9. If [#permalink]

Show Tags

19 Feb 2014, 05:24

Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________

Re: In the decimal, 2.4d7, d represents a digit from 0-9. If [#permalink]

Show Tags

05 May 2015, 12:55

Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________

After days of waiting, sharing the tension with other applicants in forums, coming up with different theories about invites patterns, and, overall, refreshing my inbox every five minutes to...

I was totally freaking out. Apparently, most of the HBS invites were already sent and I didn’t get one. However, there are still some to come out on...

In early 2012, when I was working as a biomedical researcher at the National Institutes of Health , I decided that I wanted to get an MBA and make the...