GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 17 Jul 2018, 06:54

### GMAT Club Daily Prep

#### 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

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

# If t denotes the thousandths digit in the decimal

Author Message
TAGS:

### Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 47037
If t denotes the thousandths digit in the decimal [#permalink]

### Show Tags

03 Sep 2012, 06:04
00:00

Difficulty:

5% (low)

Question Stats:

81% (00:52) correct 19% (00:53) wrong based on 1605 sessions

### HideShow timer Statistics

d = 0.43t7
If t denotes the thousandths digit in the decimal representation of d above, what digit is t?

(1) If d were rounded to the nearest hundredth, the result would be 0.44.
(2) If d were rounded to the nearest thousandth, the result would be 0.436.

Practice Questions
Question: 31
Page: 277
Difficulty: 600

_________________
Math Expert
Joined: 02 Sep 2009
Posts: 47037
Re: If t denotes the thousandths digit in the decimal [#permalink]

### Show Tags

03 Sep 2012, 06:04
5
11
SOLUTION

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

BACK TO THE ORIGINAL QUESTION:

d = 0.43t7
If t denotes the thousandths digit in the decimal representation of d above, what digit is t?

(1) If d were rounded to the nearest hundredth, the result would be 0.44. Just says that $$t\geq{5}$$. Not sufficient.

(2) If d were rounded to the nearest thousandth, the result would be 0.436. Since 7 is more than 5, then $$t$$ was rounded up to become 6, hence $$t=5$$. Sufficient.

_________________
##### General Discussion
Intern
Joined: 28 Aug 2012
Posts: 44
Location: Austria
GMAT 1: 770 Q51 V42
Re: If t denotes the thousandths digit in the decimal [#permalink]

### Show Tags

03 Sep 2012, 06:27
1
Statement (1): d is rounded up. So the thousandth digit can take the values 5, 6, 7, 8, 9. --> not sufficient
Statement (2): d is again rounded up, because the tenthousandths digit is 7. Therefore, the thousands digit is 5. --> sufficient

Answer B, Statement (2) is sufficient, Statement (1) is not sufficient.
Math Expert
Joined: 02 Sep 2009
Posts: 47037
Re: If t denotes the thousandths digit in the decimal [#permalink]

### Show Tags

07 Sep 2012, 05:29
1
SOLUTION

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

BACK TO THE ORIGINAL QUESTION:

d = 0.43t7
If t denotes the thousandths digit in the decimal representation of d above, what digit is t?

(1) If d were rounded to the nearest hundredth, the result would be 0.44. Just says that $$t\geq{5}$$. Not sufficient.

(2) If d were rounded to the nearest thousandth, the result would be 0.436. Since 7 is more than 5, then $$t$$ was rounded up to become 6, hence $$t=5$$. Sufficient.

Kudos points given to everyone with correct solution. Let me know if I missed someone.
_________________
Intern
Joined: 27 Nov 2014
Posts: 4
Re: If t denotes the thousandths digit in the decimal [#permalink]

### Show Tags

26 Dec 2014, 09:22
Not sure if B is correct.

In GMAT can we assume that rounding means rounding up if >=0.5 and rounding down if <0.5? Could also be always rounding up or down (no matter what digit)
Math Expert
Joined: 02 Sep 2009
Posts: 47037
Re: If t denotes the thousandths digit in the decimal [#permalink]

### Show Tags

26 Dec 2014, 09:25
1
noshtafoyza wrote:
Not sure if B is correct.

In GMAT can we assume that rounding means rounding up if >=0.5 and rounding down if <0.5? Could also be always rounding up or down (no matter what digit)

This is a question from Official Guide and the Official Answer is B. Rounding rules are given in the second post: if-t-denotes-the-thousandths-digit-in-the-decimal-138297.html#p1119527

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.
_________________
Manager
Joined: 23 Nov 2014
Posts: 58
Location: India
GMAT 1: 730 Q49 V40
GPA: 3.14
WE: Sales (Consumer Products)
Re: If t denotes the thousandths digit in the decimal [#permalink]

### Show Tags

19 May 2015, 15:19
Bunuel wrote:
SOLUTION

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

BACK TO THE ORIGINAL QUESTION:

d = 0.43t7
If t denotes the thousandths digit in the decimal representation of d above, what digit is t?

(1) If d were rounded to the nearest hundredth, the result would be 0.44. Just says that $$t\geq{5}$$. Not sufficient.

(2) If d were rounded to the nearest thousandth, the result would be 0.436. Since 7 is more than 5, then $$t$$ was rounded up to become 6, hence $$t=5$$. Sufficient.

If t = 4 -> d = 0.4347 = 0.435 = 0.44
=> t >= 4 not t >= 5

Am I right?
Math Expert
Joined: 02 Sep 2009
Posts: 47037
Re: If t denotes the thousandths digit in the decimal [#permalink]

### Show Tags

20 May 2015, 02:41
avgroh wrote:
Bunuel wrote:
SOLUTION

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

BACK TO THE ORIGINAL QUESTION:

d = 0.43t7
If t denotes the thousandths digit in the decimal representation of d above, what digit is t?

(1) If d were rounded to the nearest hundredth, the result would be 0.44. Just says that $$t\geq{5}$$. Not sufficient.

(2) If d were rounded to the nearest thousandth, the result would be 0.436. Since 7 is more than 5, then $$t$$ was rounded up to become 6, hence $$t=5$$. Sufficient.

If t = 4 -> d = 0.4347 = 0.435 = 0.44
=> t >= 4 not t >= 5

Am I right?

No.

When rounding to the tenth you look at only the hundredth digit, when rounding to the hundredth you look at only the thousandth digit, etc. Please re-read rounding rules given above.
_________________
e-GMAT Representative
Joined: 04 Jan 2015
Posts: 1755
Re: If t denotes the thousandths digit in the decimal [#permalink]

### Show Tags

20 May 2015, 03:04
1
avgroh wrote:
Bunuel wrote:
SOLUTION

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

BACK TO THE ORIGINAL QUESTION:

d = 0.43t7
If t denotes the thousandths digit in the decimal representation of d above, what digit is t?

(1) If d were rounded to the nearest hundredth, the result would be 0.44. Just says that $$t\geq{5}$$. Not sufficient.

(2) If d were rounded to the nearest thousandth, the result would be 0.436. Since 7 is more than 5, then $$t$$ was rounded up to become 6, hence $$t=5$$. Sufficient.

If t = 4 -> d = 0.4347 = 0.435 = 0.44
=> t >= 4 not t >= 5

Am I right?

Hi avgroh,

St-I talks about rounding off to the nearest hundredth. Since the number is 0.43t7 and 3 is at the hundredths place, for rounding off to the nearest hundredth we will only consider the value of the digit next to it. As 0.43t7 has been rounded off to 0.44 that would mean t =>5.

Rounding off from the right most digit is not the right way to go about rounding off process. Think of it this way: Consider the number 1.448 which is to be rounded off to the nearest tenths. If you start from the right most digit you would round off it as 1.448 -> 1.45 -> 1.5.
But 1.448 is nearer to 1.4 than to 1.5, right? Hence the only thing that should matter is the next digit to which a number is to be rounded off. Hence for the number 1.448, to round it off to the nearest tenths, the digit next to tenths place i.e. 4 should matter and it should be rounded off to 1.4.

Hope it's clear

Regards
Harsh
_________________

Ace GMAT quant
Articles and Question to reach Q51 | Question of the week

Number Properties – Even Odd | LCM GCD
Word Problems – Percentage 1 | Percentage 2 | Time and Work 1 | Time and Work 2 | Time, Speed and Distance 1 | Time, Speed and Distance 2
Advanced Topics- Permutation and Combination 1 | Permutation and Combination 2 | Permutation and Combination 3 | Probability
Geometry- Triangles 1 | Triangles 2 | Triangles 3 | Common Mistakes in Geometry
Algebra- Wavy line

Practice Questions
Number Properties 1 | Number Properties 2 | Algebra 1 | Geometry | Prime Numbers | Absolute value equations | Sets

| '4 out of Top 5' Instructors on gmatclub | 70 point improvement guarantee | www.e-gmat.com

Target Test Prep Representative
Affiliations: Target Test Prep
Joined: 04 Mar 2011
Posts: 2669
Re: If t denotes the thousandths digit in the decimal [#permalink]

### Show Tags

09 Aug 2016, 13:41
1
Quote:
d = 0.43t7
If t denotes the thousandths digit in the decimal representation of d above, what digit is t?

(1) If d were rounded to the nearest hundredth, the result would be 0.44.
(2) If d were rounded to the nearest thousandth, the result would be 0.436.

We are given that t denotes the thousandths digit of 0.43t7. We need to determine the value of t.

Statement One Alone:

If d were rounded to the nearest hundredth, the result would be 0.44.

Using the information in statement one, t could be different values. For example, t could be 5 (so that d would be 0.4357) or t could be 6 (so that d would be 0.4367). Similarly, t could also be 7, 8, or 9. Notice in any of these cases, d rounds up to 0.44.

Thus, statement one is not enough information to answer the question. We can eliminate answer choices A and D.

Statement Two Alone:

If d were rounded to the nearest thousandth, the result would be 0.436.

Using the information from statement two, d must be 0.4357. Because of the “7” in the ten-thousandths digit, we see that 0.43t7 will only round up to 0.436. Thus, t can only be the value 5. Any other value of t will not round d to 0.436 when rounded to the nearest thousandth. Statement two is sufficient to answer the question.

_________________

Jeffery Miller

GMAT Quant Self-Study Course
500+ lessons 3000+ practice problems 800+ HD solutions

Non-Human User
Joined: 09 Sep 2013
Posts: 7271
Re: If t denotes the thousandths digit in the decimal [#permalink]

### Show Tags

11 Aug 2017, 14:26
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: If t denotes the thousandths digit in the decimal   [#permalink] 11 Aug 2017, 14:26
Display posts from previous: Sort by

# Events & Promotions

 Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.