It is currently 19 Oct 2017, 06:03

### 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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# x=1+0.01*d, d is a positive integer and d<10 what is the

Author Message
VP
Joined: 10 Jun 2007
Posts: 1434

Kudos [?]: 350 [0], given: 0

x=1+0.01*d, d is a positive integer and d<10 what is the [#permalink]

### Show Tags

24 Sep 2007, 16:20
00:00

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions

### HideShow timer Statistics

This topic is locked. If you want to discuss this question please re-post it in the respective forum.

x=1+0.01*d, d is a positive integer and d<10
what is the value of d?

1) 2<=d<=4
2) The thousandth digit of 10(x^2)＝ the hundredth digit of x^2

Kudos [?]: 350 [0], given: 0

VP
Joined: 09 Jul 2007
Posts: 1098

Kudos [?]: 141 [0], given: 0

Location: London

### Show Tags

24 Sep 2007, 18:30
x=1+0.01*d, d is a positive integer and d<10
what is the value of d?

1) 2<=d<=4
2) The thousandth digit of 10(x^2)＝ the hundredth digit of x^2[/quote]

1. doesnt give deff. answer, so insuff. alon
2. not enough info again, d can be max. 9 then can 10(x^2) be 1000 or a greater number? the staement says 10(x^2) has a thousands digit.

i would go with E.
or something is missing
or my reasoning is wroing

Kudos [?]: 141 [0], given: 0

VP
Joined: 10 Jun 2007
Posts: 1434

Kudos [?]: 350 [0], given: 0

### Show Tags

25 Sep 2007, 14:27
OA=B

x=1+0.01*d, d is a positive integer and d<10
what is the value of d?

1) 2<=d<=4
2) The thousandth digit of 10(x^2)＝ the hundredth digit of x^2

We know from the question that d can be 1,2,3,...,9
For (1) This is obviously INSUFFICIENT since d can be 2, 3, 4
For (2) we know that
If d=1,2,3,4,...,9, then x equals 1.01, 1.02, 1.03, 1.04...,1.09
Then we know that x^2 equals 1.0201, 1.0404, 1.0609, 1.0816, etc...
Therefore, 10*(x^2) will be 10.201, 10.404, 10.609, 10.816, etc...

Now, we can create a table:
(d, thousandth digit of 10*(x^2), hundredth digit of x^2)
(1, 1, 2)
(2, 4, 4)
(3, 9, 6)
(4, 6, 8)
etc...
If you look at the pattern, the question is asking when is the digit unit of d^2 ever equals to 2d knowing that 1<=d<=9. This is only true when d=2. Therefore, B is sufficient.

Cheers.

Kudos [?]: 350 [0], given: 0

VP
Joined: 09 Jul 2007
Posts: 1098

Kudos [?]: 141 [0], given: 0

Location: London

### Show Tags

25 Sep 2007, 15:50
bkk145 wrote:
x=1+0.01*d, d is a positive integer and d<10
what is the value of d?

1) 2<=d<=4
2) The thousandth digit of 10(x^2)＝ the hundredth digit of x^2

Oooops, i messed thousands with thousandth

thanks Bkk

Kudos [?]: 141 [0], given: 0

Re: DS   [#permalink] 25 Sep 2007, 15:50
Display posts from previous: Sort by