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

 It is currently 21 Jun 2018, 10:54

### 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

# Events & Promotions

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

# If d=(1)/((2^3)(5^7)) is expressed as a terminating decimal

Author Message
TAGS:

### Hide Tags

Intern
Joined: 17 Oct 2011
Posts: 14
Location: Taiwan
GMAT 1: 590 Q39 V34
GMAT 2: 680 Q47 V35
If d=(1)/((2^3)(5^7)) is expressed as a terminating decimal [#permalink]

### Show Tags

02 Mar 2012, 04:20
3
37
00:00

Difficulty:

55% (hard)

Question Stats:

56% (00:47) correct 44% (01:05) wrong based on 877 sessions

### HideShow timer Statistics

If d=(1)/((2^3)(5^7)) is expressed as a terminating decimal, how many nonzero digits will d have?

A. One
B. Two
C. Three
D. Seven
E. Ten
Math Expert
Joined: 02 Sep 2009
Posts: 46264

### Show Tags

02 Mar 2012, 04:29
25
17
wizard wrote:
If d=(1)/((2^3)(5^7)) is expressed as a terminating decimal, how many nonzero digits will d have?

A. One
B. Two
C. Three
D. Seven
E. Ten

Given: $$d=\frac{1}{2^3*5^7}$$.

Multiply by $$\frac{2^4}{2^4}$$ --> $$d=\frac{2^4}{(2^3*5^7)*2^4}=\frac{2^4}{2^7*5^7}=\frac{2^4}{10^7}=\frac{16}{10^7}=0.0000016$$. Hence $$d$$ will have two non-zero digits, 16, when expressed as a decimal.

_________________
Senior Manager
Joined: 23 Oct 2010
Posts: 364
Location: Azerbaijan
Concentration: Finance
Schools: HEC '15 (A)
GMAT 1: 690 Q47 V38
Re: If d=(1)/((2^3)(5^7)) is expressed as a terminating decimal [#permalink]

### Show Tags

02 Mar 2012, 05:31
1/2^3*5^7=1/10^3*1/5^4=10^(-3)*0.2^4

2^4=4^2 =16
_________________

Happy are those who dream dreams and are ready to pay the price to make them come true

I am still on all gmat forums. msg me if you want to ask me smth

Senior Manager
Joined: 15 Oct 2015
Posts: 341
Concentration: Finance, Strategy
GPA: 3.93
WE: Account Management (Education)
Re: If d=(1)/((2^3)(5^7)) is expressed as a terminating decimal [#permalink]

### Show Tags

03 Mar 2016, 05:44
Bunuel wrote:
wizard wrote:
If d=(1)/((2^3)(5^7)) is expressed as a terminating decimal, how many nonzero digits will d have?

A. One
B. Two
C. Three
D. Seven
E. Ten

Given: $$d=\frac{1}{2^3*5^7}$$.

Multiply by $$\frac{2^4}{2^4}$$ --> $$d=\frac{2^4}{(2^3*5^7)*2^4}=\frac{2^4}{2^7*5^7}=\frac{2^4}{10^7}=\frac{16}{10^7}=0.0000016$$. Hence $$d$$ will have two non-zero digits, 16, when expressed as a decimal.

But I thought it was gonna change the value.
But that does nothing to the ratio. I didn't think hard.
U just check Buñuel's solution if want the smartest detailed solution.
take kudos
Manager
Joined: 04 May 2014
Posts: 162
Location: India
WE: Sales (Mutual Funds and Brokerage)
Re: If d=(1)/((2^3)(5^7)) is expressed as a terminating decimal [#permalink]

### Show Tags

16 Aug 2017, 20:59
1/5=0.2
2⁻³*5⁻³*0.2⁴
now 0.2⁴=0.0016
Hence 2 non zero nos.
Re: If d=(1)/((2^3)(5^7)) is expressed as a terminating decimal   [#permalink] 16 Aug 2017, 20:59
Display posts from previous: Sort by