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 →

Natural Numbers

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Master | Next Rank: 500 Posts
Posts: 304
Joined: Wed Jan 27, 2010 8:35 amFollowed by: 3 members
Location: International Space Station
Thanked: 11 times
by Aman verma » Sun Feb 21, 2010 2:12 am
Q: All the natural numbers less than 1000 but not containing the digit 5 are arranged horizontally in descending order .What is the 555th number on the list ?

a) 111

b)182

c)213

d)284

e)315
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Source: — Problem Solving |
User avatar
Legendary Member
Posts: 1132
Joined: Mon Jul 20, 2009 3:38 amFollowed by: 6 members
Location: India
Thanked: 64 times
GMAT Score:760

by harsh.champ » Sun Feb 21, 2010 2:16 am
Aman verma wrote:Q: All the natural numbers less than 1000 but not containing the digit 5 are arranged horizontally in descending order .What is the 555th number on the list ?

a) 111

b)182

c)213

d)284

e)315
Now,
If 5 is there,we get 445.
NOw,555/5=111
Hence,subtracting we get 334.
111/5=22.2
Hence we get 310
22.2/5 =4.44
Hence,315 E. is the answer
It takes time and effort to explain, so if my comment helped you please press Thanks button :)



Just because something is hard doesn't mean you shouldn't try,it means you should just try harder.

"Keep Walking" - Johnny Walker :P
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Legendary Member
Posts: 1022
Joined: Mon Jul 20, 2009 11:49 pmFollowed by: 2 members
Location: Gandhinagar
Thanked: 41 times

by shashank.ism » Sun Feb 21, 2010 2:39 am
Aman verma wrote:Q: All the natural numbers less than 1000 but not containing the digit 5 are arranged horizontally in descending order .What is the 555th number on the list ?

a) 111

b)182

c)213

d)284

e)315
the no. would be arranged (without excluding digit 5 ) 1000, 999,998,,,,,,,,,,,,,,,,1
so 555 no. will be 1000-555 +1 = 446
now we exclude alll digit having 5
now 555/5 =111 these are all unit digits..
again 55/5 = 11 --> 11x9 = 99
again 5/5= 1 --> 45 -10 -5 = 30
so subtract 111+99+30= 122
446-240 = 206

I think I m doing some mistake her ..but it will be around 213 Ans C
My Websites:
www.mba.webmaggu.com - India's social Network for MBA Aspirants

www.deal.webmaggu.com -India's online discount, coupon, free stuff informer.

www.dictionary.webmaggu.com - A compact free online dictionary with images.

Nothing is Impossible, even Impossible says I'm possible.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Master | Next Rank: 500 Posts
Posts: 304
Joined: Wed Jan 27, 2010 8:35 amFollowed by: 3 members
Location: International Space Station
Thanked: 11 times

by Aman verma » Sun Feb 21, 2010 3:09 am
Ans: [spoiler]c) 213[/spoiler].But I don't have the solution.If anybody could provide the correct solution...
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Legendary Member
Posts: 1275
Joined: Thu Sep 21, 2006 11:13 pmFollowed by: 2 members
Location: Arabian Sea
Thanked: 125 times

by ajith » Sun Feb 21, 2010 3:27 am
Aman verma wrote:Q: All the natural numbers less than 1000 but not containing the digit 5 are arranged horizontally in descending order .What is the 555th number on the list ?
Let us see how many natural numbers are there between 1 to 1000; containing 5

1-100 (10+9) - 19


1-499 => 19*5
500-599 = 100
600-999 = 19*4

Total = 19*9+100

There are 271 numbers

No of other numbers(not containing 9) = 729

Out of these we need to find out 555th in descending order

or (729-555) = 174th in ascending order

There are 81 between 1-100
there are 81 between 101-200
162
9 more between 200-210 ; total 171
213 is the 174th
Always borrow money from a pessimist, he doesn't expect to be paid back.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Legendary Member
Posts: 1132
Joined: Mon Jul 20, 2009 3:38 amFollowed by: 6 members
Location: India
Thanked: 64 times
GMAT Score:760

by harsh.champ » Sun Feb 21, 2010 3:29 am
Aman verma wrote:Ans: [spoiler]c) 213[/spoiler].But I don't have the solution.If anybody could provide the correct solution...
Hey Aman,
You have written that the OA is C.I found the answer to be E.
I am posting my method below:-
If 5 is there,we get 445.
NOw,555/5=111
Hence,subtracting we get 334.
111/5=22.2
Hence we get 310
22.2/5 =4.44
Hence,315 E. is the answer
Can someone guide me where I went wrong??
Thanks in advance.
It takes time and effort to explain, so if my comment helped you please press Thanks button :)



Just because something is hard doesn't mean you shouldn't try,it means you should just try harder.

"Keep Walking" - Johnny Walker :P
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Legendary Member
Posts: 1275
Joined: Thu Sep 21, 2006 11:13 pmFollowed by: 2 members
Location: Arabian Sea
Thanked: 125 times

by ajith » Sun Feb 21, 2010 3:32 am
harsh.champ wrote: Hey Aman,
You have written that the OA is C.I found the answer to be E.
I am posting my method below:-
If 5 is there,we get 445.
NOw,555/5=111
Hence,subtracting we get 334.
111/5=22.2
Hence we get 310
22.2/5 =4.44
Hence,315 E. is the answer
Can someone guide me where I went wrong??
Thanks in advance.
If 5 is there we get 445?

I do not get that statement
I do not get why you did the rest of the stuff either
Always borrow money from a pessimist, he doesn't expect to be paid back.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Legendary Member
Posts: 1132
Joined: Mon Jul 20, 2009 3:38 amFollowed by: 6 members
Location: India
Thanked: 64 times
GMAT Score:760

by harsh.champ » Sun Feb 21, 2010 3:39 am
ajith wrote:
harsh.champ wrote: Hey Aman,
You have written that the OA is C.I found the answer to be E.
I am posting my method below:-
If 5 is there,we get 445.
NOw,555/5=111
Hence,subtracting we get 334.
111/5=22.2
Hence we get 310
22.2/5 =4.44
Hence,315 E. is the answer
Can someone guide me where I went wrong??
Thanks in advance.
If 5 is there we get 445?

I do not get that statement
I do not get why you did the rest of the stuff either
Ok,I will explain it to you-step by step.
In the question,it is written-
but not containing the digit 5 are arranged horizontally
Lets assume those no.s are included.
Then 1000,999,998,997,.........................,445-This will be the 555th no.-Agreed.
Now, I am subtracting those no.s which are divisible by 5(1000,995,....)
SO you get 555/5=111 numbers-Agreed
Now,I have also counted 111/5 nos. i.e 22.2
Like this I had adopted my approach.
I know that the answer does not match with the OA but I can't seem to figure out where I went wrong .
It takes time and effort to explain, so if my comment helped you please press Thanks button :)



Just because something is hard doesn't mean you shouldn't try,it means you should just try harder.

"Keep Walking" - Johnny Walker :P
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Legendary Member
Posts: 1275
Joined: Thu Sep 21, 2006 11:13 pmFollowed by: 2 members
Location: Arabian Sea
Thanked: 125 times

by ajith » Sun Feb 21, 2010 4:12 am
harsh.champ wrote:
Ok,I will explain it to you-step by step.
In the question,it is written-
but not containing the digit 5 are arranged horizontally
Lets assume those no.s are included.
Then 1000,999,998,997,.........................,445-This will be the 555th no.-Agreed.
Now, I am subtracting those no.s which are divisible by 5(1000,995,....)
SO you get 555/5=111 numbers-Agreed
Now,I have also counted 111/5 nos. i.e 22.2
Like this I had adopted my approach.
I know that the answer does not match with the OA but I can't seem to figure out where I went wrong .
your approach doesnt take into account numbers from 500-599 all of them has 5
moreover it doesnt take care of 50-59

and it is not logical to deduct powers of 5
Always borrow money from a pessimist, he doesn't expect to be paid back.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Master | Next Rank: 500 Posts
Posts: 102
Joined: Sat Feb 20, 2010 5:38 am
Location: IIM Ahmedabad
Thanked: 10 times

by firdaus117 » Sun Feb 21, 2010 4:20 am
Lets consider three digit number without 5 as 'HTO' where H,T,O are respectively digits at hundreds,tens and ones place.
Now,we start counting the numbers from 999,998,997 i.e. in descending order.
Now, H can be 9,8,7,6,4,3,2 and 1.Total 8 values.
T and O each can take 9 values from 0 to 9 except 5.
Total numbers=8*9*9=648
Now exclude numbers in range 100-199=9*9=81 numbers from 648 values.
Remaining numbers=648-81=567 values.(Still we need to lessen 567-555=12 numbers)
Now there are 9 values b/w 200-209.210,211 and 212 are the remaining three.
The countdown stops at 213 for 555th number. :D
[/u]
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Legendary Member
Posts: 1022
Joined: Mon Jul 20, 2009 11:49 pmFollowed by: 2 members
Location: Gandhinagar
Thanked: 41 times

by shashank.ism » Sun Feb 21, 2010 5:47 am
harsh.champ wrote:
Aman verma wrote:Ans: [spoiler]c) 213[/spoiler].But I don't have the solution.If anybody could provide the correct solution...
Hey Aman,
You have written that the OA is C.I found the answer to be E.
I am posting my method below:-
If 5 is there,we get 445.
NOw,555/5=111
Hence,subtracting we get 334.
111/5=22.2
Hence we get 310
22.2/5 =4.44
Hence,315 E. is the answer
Can someone guide me where I went wrong??
Thanks in advance.
Harsh you have left many numbers in between

like number with 5xx = 45-10 -5
number with x5x =11x9 ==99
number at end = 5 = 111
though i was not able to get exact ans but I was near solution ...U left the numbers 5xx and x5x....please consider those numbers..u will get to the solution..
meanwhile I m checking ajith ans...he has solved the problem .well...
My Websites:
www.mba.webmaggu.com - India's social Network for MBA Aspirants

www.deal.webmaggu.com -India's online discount, coupon, free stuff informer.

www.dictionary.webmaggu.com - A compact free online dictionary with images.

Nothing is Impossible, even Impossible says I'm possible.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1