November 20, 2018 November 20, 2018 09:00 AM PST 10:00 AM PST The reward for signing up with the registration form and attending the chat is: 6 free examPAL quizzes to practice your new skills after the chat. November 20, 2018 November 20, 2018 06:00 PM EST 07:00 PM EST What people who reach the high 700's do differently? We're going to share insights, tips and strategies from data we collected on over 50,000 students who used examPAL.
Author 
Message 
TAGS:

Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 50672

If x, y, and z are integers and (2^x)*(5^y)*z = 0.00064, what is the
[#permalink]
Show Tags
06 Nov 2014, 08:18
Question Stats:
68% (02:05) correct 32% (02:04) wrong based on 300 sessions
HideShow timer Statistics



Intern
Joined: 27 Jul 2012
Posts: 25

Re: If x, y, and z are integers and (2^x)*(5^y)*z = 0.00064, what is the
[#permalink]
Show Tags
06 Nov 2014, 12:24
Statement 1 can be simplified to achieve 2^x*5^y*z=2*5^(5) if z=2^2*5 then 2^x*5^y = 2^1*5^4 From this we see x=1, 5=4, thus we can find xy.
Statement 2 is not enough as value of y would depend on value of z which is still unkown. 5^y*z=2^2*5^5. Insufficient to find answer



Manager
Joined: 22 Sep 2012
Posts: 133
Concentration: Strategy, Technology
WE: Information Technology (Computer Software)

Re: If x, y, and z are integers and (2^x)*(5^y)*z = 0.00064, what is the
[#permalink]
Show Tags
06 Nov 2014, 18:59
2^x*5^y*z= 64 * 10^5 = 2^6*2^5*5^5 = 2^1*5^5
Statement 1 : z = 20 We can write 2^1*5^5 = 2^1*5^6 *2^2*5^1 = 2^1*5^6*20 Since z =20, then x = 1 and y=6 Sufficient
Statement 2: x = –1 Since we don't know the value of z, we cannot determine the value of 5^y. Therefore, Statement 2 is insufficient
Answer should be A



Intern
Joined: 23 Oct 2012
Posts: 46

Re: If x, y, and z are integers and (2^x)*(5^y)*z = 0.00064, what is the
[#permalink]
Show Tags
06 Nov 2014, 21:55
2^x 5^y z = .00064 statement 1  z=20 clearly sufficient. statement 2  x=1 5^y * z = 128/10^5 5^y * z = 2^2 5^5 y=5 and x= 1 xy=5. sufficient. OA is D. Bunuel, please confirm.
_________________
Kudos please!



Senior Manager
Joined: 02 Dec 2014
Posts: 381
Location: Russian Federation
Concentration: General Management, Economics
WE: Sales (Telecommunications)

Re: If x, y, and z are integers and (2^x)*(5^y)*z = 0.00064, what is the
[#permalink]
Show Tags
19 Dec 2014, 04:18
If x, y, and z are integers and (2^x)*(5^y)*z = 0.00064, what is the value of xy? (1) z = 20 (2) x = –1 Here is my version. 1) if z=20 ==> 2^(x)*5^(y)=(0.00064/20)=0.000032 ==> 2^(x)*5^(y)=32*10^(6) ==> 2^(x)*5^(y)=2^(5)*(2*5)^(6) ==>x=1 and y=6 ==>xy=6 2) We know x=1 but nothing is said about z. Hence not sufficient. Hope it is clear
_________________
"Are you gangsters?"  "No we are Russians!"



Intern
Joined: 27 Nov 2014
Posts: 5

Re: If x, y, and z are integers and (2^x)*(5^y)*z = 0.00064, what is the
[#permalink]
Show Tags
20 Dec 2014, 14:39
navkaran wrote: Statement 1 can be simplified to achieve 2^x*5^y*z=2*5^(5) if z=2^2*5 then 2^x*5^y = 2^1*5^4 From this we see x=1, 5=4, thus we can find xy.
Statement 2 is not enough as value of y would depend on value of z which is still unkown. 5^y*z=2^2*5^5. Insufficient to find answer Hi navkaran: Can you please elaborate how you go from "..if z=2^2*5" to "..then 2^x*5^y = 2^1*5^4". My reason is that I am getting a different value for y only, just want to make sure my methods aren't incorrect. Thank you.



Manager
Joined: 21 Jul 2014
Posts: 72
Location: United States
Schools: HBS '16, Stanford '16, Kellogg '16, CBS '16, Ross '17, Haas '16, Haas EWMBA '18, Tuck '17, Stern '18, Yale '17, Anderson '17, Darden '16, Johnson '16, Tepper '18 (D), LBS '17, Insead '14, IMD '16, IE Nov'15, Booth, LBS MiM'17
WE: Project Management (NonProfit and Government)

Re: If x, y, and z are integers and (2^x)*(5^y)*z = 0.00064, what is the
[#permalink]
Show Tags
14 Jan 2015, 20:39
The statement asks 2^x . 5^y. z = 0.00064 which can be translated into prime factors as
Statement 1: 2^x . 5^y. z = 2^6 . 10^ 6 = 2^0 . 5^ 6 comparing both the parts we get x= 0 & y=6 so xy= 0 sufficient.
Statement 2: 5^y . z = 0.000128 which means y & z can take any values. not sufficient.
Therefore A.



Director
Joined: 26 Oct 2016
Posts: 641
Location: United States
Concentration: Marketing, International Business
GPA: 4
WE: Education (Education)

Re: If x, y, and z are integers and (2^x)*(5^y)*z = 0.00064, what is the
[#permalink]
Show Tags
03 Mar 2017, 13:04
JusTLucK04 wrote: If x, y, and z are integers and 2x 5yz = 6.4 × 106, what is the value of xy? (1) z = 20 (2) x = 9 Posting solution for above problem.
Attachments
official_new.PNG [ 94.17 KiB  Viewed 2183 times ]
_________________
Thanks & Regards, Anaira Mitch



Senior Manager
Status: Come! Fall in Love with Learning!
Joined: 05 Jan 2017
Posts: 496
Location: India

Re: If x, y, and z are integers and (2^x)*(5^y)*z = 0.00064, what is the
[#permalink]
Show Tags
04 Mar 2017, 05:24
(2^x)(5^y)z = 64 x 10^5 St 1: z = 20. therefore (2^x)(5^y) = 32 x 10^6 = 2^5 x (5 x 2)^6 = 2^1 x 5^6. Hence, x = 1 and y = 6. xy = 6. ANSWER St 2: x = 9. no idea about z. INSUFFICIENT. Option A
_________________
GMAT Mentors



Manager
Joined: 11 May 2018
Posts: 94
Location: India

Re: If x, y, and z are integers and (2^x)*(5^y)*z = 0.00064, what is the
[#permalink]
Show Tags
30 Aug 2018, 22:24
Please someone explain Statement 2:
statement 2 
x=1 substitute x in the given equation. 2^1 * 5^y * z = 64* 10^5 5^y * z = 2^2 5^5
y=5 and x= 1
xy=5. sufficient.
why cannot the OA be D Bunuel nightblade354
_________________
If you want to Thank me Give me a KUDOS "I’ve spent months preparing for the day I’d face you. I’ve come a long way, GMAT" SonGoku



Math Expert
Joined: 02 Sep 2009
Posts: 50672

Re: If x, y, and z are integers and (2^x)*(5^y)*z = 0.00064, what is the
[#permalink]
Show Tags
30 Aug 2018, 22:43




Re: If x, y, and z are integers and (2^x)*(5^y)*z = 0.00064, what is the &nbs
[#permalink]
30 Aug 2018, 22:43






