BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem
TTP OnDemand GMAT Video Course
Featured Course

Target Test Prep GMAT OnDemand

Scott Woodbury-Stewart’s private virtual classroom — 400 hours of master-class video lessons for the GMAT Focus Edition.

  • 715+ score guarantee — highest in the industry (99th percentile)
  • 52 chapters · 1,500+ lessons · 4,000+ practice questions
  • 400 hours of video · 1,500+ instructor-led HD smartboard lessons
  • 300,000+ students accepted to Harvard, Stanford, Wharton, Booth & Sloan & more
  • 24/7 live support + weekly Zoom office hours with GMAT instructors
  • TTP AI Assist — 24/7 AI-powered virtual tutor for instant help
  • 1,200+ flashcards + AI-powered study assistant & daily calendar
  • OnDemand, LiveTeach & GMAT Bootcamp formats available
  • Also: GRE, SAT Math & Executive Assessment courses
  • MBA Admissions Consulting now available
  • 🏆 2025 EdTech Breakthrough Award: Test Prep Solution Provider of the Year
  • 200,000+ students served
  • 5-day free trial — $0 to start, no auto-billing, cancel anytime
★★★★★ 5.0 (559 reviews)
130-pt guarantee
$0 to start then $127/mo
Start Free 5-Day Trial Read 559 Reviews →

exponents

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Senior | Next Rank: 100 Posts
Posts: 94
Joined: Tue Oct 14, 2008 1:05 pm
by simba12123 » Tue Nov 04, 2008 8:51 pm
If x and y are integers and

(15x + 15^(x+1))/ 4y = 15y,

what is the value of x?

2
3
4
5
Cannot be determined


cant we backsolve this bad boy? What is the best and most sure shot way?
Advancing to be reckoned with!
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Source: — Problem Solving |
Master | Next Rank: 500 Posts
Posts: 154
Joined: Tue Aug 26, 2008 12:59 pm
Location: Canada
Thanked: 4 times

by canuckclint » Tue Nov 04, 2008 9:14 pm
i say it cannot be determined because we don't know y.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Legendary Member
Posts: 574
Joined: Sun Jun 01, 2008 8:48 am
Location: Bangalore
Thanked: 28 times

by vishubn » Tue Nov 04, 2008 9:27 pm
Is the problem free of typo????


i mean x and y !! two different unknowns !! First glance one can know "IT CANT BE DETERMINED"

any more comments???


Vishu
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Legendary Member
Posts: 2134
Joined: Mon Oct 20, 2008 11:26 pmFollowed by: 25 members
Thanked: 237 times
GMAT Score:730

Re: exponents

by logitech » Tue Nov 04, 2008 9:51 pm
simba12123 wrote:If x and y are integers and

(15x + 15^(x+1))/ 4y = 15y,

what is the value of x?

2
3
4
5
Cannot be determined


cant we backsolve this bad boy? What is the best and most sure shot way?
There has to be a typo. I assume that the questions reads like this:

(15^X + 15^(x+1))/ 4y = 15y

SO;

15^x+15^x15=15 4y^2

15^x(15+1)=15 4y^2

15^x = (15 y^2 ) /4

SO I belive this is where the magic is:

8)

15^x = 15 (y^2 /4)

15^x can be 1, 15, 15^2,....

Who wants to take it from here ?
:lol:
LGTCH
---------------------
"DON'T LET ANYONE STEAL YOUR DREAM!"
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Legendary Member
Posts: 574
Joined: Sun Jun 01, 2008 8:48 am
Location: Bangalore
Thanked: 28 times

by vishubn » Tue Nov 04, 2008 10:02 pm
Who wants to take it from here ?
Laughing
so further doing it !!
we knw x and y are integers

y^2=((15^x)*4)/15

so Left hand side should be a perfect square

a) we get y^2=60 not a perfect square
b) we get y^2=900 and y=30 , possible answer
c)we get y^2=13500 not a perfect square
d) we get y^2=202500 y=450 , possible answer !!

stuck betwwen B and D

Any more attemptS??

Vishu
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Legendary Member
Posts: 1159
Joined: Wed Apr 16, 2008 10:35 pm
Thanked: 56 times

by raunekk » Tue Nov 04, 2008 10:41 pm
there is a typo here,,,

https://www.beatthegmat.com/i-don-t-unde ... 15609.html


thanks,...
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Legendary Member
Posts: 2134
Joined: Mon Oct 20, 2008 11:26 pmFollowed by: 25 members
Thanked: 237 times
GMAT Score:730

by logitech » Tue Nov 04, 2008 10:51 pm
raunekk wrote:there is a typo here,,,

https://www.beatthegmat.com/i-don-t-unde ... 15609.html


thanks,...
Thanks man! - I mean MAJOR TYPO!!
LGTCH
---------------------
"DON'T LET ANYONE STEAL YOUR DREAM!"
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Legendary Member
Posts: 574
Joined: Sun Jun 01, 2008 8:48 am
Location: Bangalore
Thanked: 28 times

by vishubn » Wed Nov 05, 2008 12:05 am
WOW!!!
Way tooo off league !!

Vishu

thanks again
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Senior | Next Rank: 100 Posts
Posts: 94
Joined: Tue Oct 14, 2008 1:05 pm

yes

by simba12123 » Wed Nov 05, 2008 8:23 am
Logitech hit the nail on the head. The question does stand corrected!
Advancing to be reckoned with!
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Master | Next Rank: 500 Posts
Posts: 207
Joined: Sun Mar 11, 2007 6:16 pm
Location: Mumbai
Thanked: 11 times

Re: yes

by jimmiejaz » Wed Nov 05, 2008 8:43 am
simba12123 wrote:Logitech hit the nail on the head. The question does stand corrected!
He corrected it on part :)
the powers of y also needed to be corrected!!!!!!
anyways keep rocking guys!!!!!
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1