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

It is currently 19 Oct 2019, 07:49

Close

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
Your Progress

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

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Close

Request Expert Reply

Confirm Cancel

What is the tens digit of two-digit positive integer w?

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Find Similar Topics 
GMAT Instructor
avatar
B
Joined: 04 Jul 2006
Posts: 1133
Location: Madrid
What is the tens digit of two-digit positive integer w?  [#permalink]

Show Tags

New post 21 Feb 2019, 12:52
00:00
A
B
C
D
E

Difficulty:

  85% (hard)

Question Stats:

40% (02:33) correct 60% (02:44) wrong based on 40 sessions

HideShow timer Statistics

What is the tens digit of two-digit positive integer w?

(1) The tens digit of 2w is equal to the tens digit of w.
(2) The sum of the digits of w+5 is 5.
Manager
Manager
avatar
G
Joined: 12 Apr 2011
Posts: 149
Location: United Arab Emirates
Concentration: Strategy, Marketing
Schools: CBS '21, Yale '21, INSEAD
GMAT 1: 670 Q50 V31
GMAT 2: 720 Q50 V37
WE: Marketing (Telecommunications)
Re: What is the tens digit of two-digit positive integer w?  [#permalink]

Show Tags

New post 21 Feb 2019, 13:26
kevincan wrote:
What is the tens digit of two-digit positive integer w?

(1) The tens digit of 2w is equal to the tens digit of w.
(2) The sum of the digits of w+5 is 5.


This took a while to solve!

from statement 1 we are told that 2*w and w share the same number in the tens digit.
now lets assume w is either from 10-20----90s or 19-29-39---99 series to test the extremes:
hence:
If w is:
10-20-30-40-50-60-70-80-90
2w will be:
20-40-60-80-100-120-140-160-180

or 2nd case:
w is
19-29-39-49-59-69-79-89-99
2w will be:
38-58-78-98-118-138-158-178-198

from the above we see only if w = 99 then 2w = 198 and satisfies the first statement. We also have other solutions such 95, 96, 97, 98, 99
Hence 1 is insufficient

Now in the second statement we are told: w+5 leads to a digit whose sum is 5.
Possible solutions are: 23, 32, 41, 50, 104
i.e. w = 18, 27, 36, 45, or 99
Again 2 is insufficient.

But if we combine 1 & 2 we get w=99

Hence both are required and C is the correct answer.
_________________
Hit Kudos if you like what you see!
Intern
Intern
avatar
B
Joined: 19 Jan 2017
Posts: 20
Re: What is the tens digit of two-digit positive integer w?  [#permalink]

Show Tags

New post 21 Feb 2019, 19:04
eabhgoy wrote:
kevincan wrote:
What is the tens digit of two-digit positive integer w?

(1) The tens digit of 2w is equal to the tens digit of w.
(2) The sum of the digits of w+5 is 5.


This took a while to solve!

from statement 1 we are told that 2*w and w share the same number in the tens digit.
now lets assume w is either from 10-20----90s or 19-29-39---99 series to test the extremes:
hence:
If w is:
10-20-30-40-50-60-70-80-90
2w will be:
20-40-60-80-100-120-140-160-180

or 2nd case:
w is
19-29-39-49-59-69-79-89-99
2w will be:
38-58-78-98-118-138-158-178-198

from the above we see only if w = 99 then 2w = 198 and satisfies the first statement. We also have other solutions such 95, 96, 97, 98, 99
Hence 1 is insufficient

Now in the second statement we are told: w+5 leads to a digit whose sum is 5.
Possible solutions are: 23, 32, 41, 50, 104
i.e. w = 18, 27, 36, 45, or 99
Again 2 is insufficient.

But if we combine 1 & 2 we get w=99

Hence both are required and C is the correct answer.


The question is asking for only the tens digit, so therefore 1 is sufficient and two is insufficient since 27 and 99 can both be possible solutions.

Therefore answer is A
Manager
Manager
avatar
G
Joined: 12 Apr 2011
Posts: 149
Location: United Arab Emirates
Concentration: Strategy, Marketing
Schools: CBS '21, Yale '21, INSEAD
GMAT 1: 670 Q50 V31
GMAT 2: 720 Q50 V37
WE: Marketing (Telecommunications)
Re: What is the tens digit of two-digit positive integer w?  [#permalink]

Show Tags

New post 21 Feb 2019, 22:42
truplayer257 wrote:
eabhgoy wrote:
kevincan wrote:
What is the tens digit of two-digit positive integer w?

(1) The tens digit of 2w is equal to the tens digit of w.
(2) The sum of the digits of w+5 is 5.


This took a while to solve!

from statement 1 we are told that 2*w and w share the same number in the tens digit.
now lets assume w is either from 10-20----90s or 19-29-39---99 series to test the extremes:
hence:
If w is:
10-20-30-40-50-60-70-80-90
2w will be:
20-40-60-80-100-120-140-160-180

or 2nd case:
w is
19-29-39-49-59-69-79-89-99
2w will be:
38-58-78-98-118-138-158-178-198

from the above we see only if w = 99 then 2w = 198 and satisfies the first statement. We also have other solutions such 95, 96, 97, 98, 99
Hence 1 is insufficient

Now in the second statement we are told: w+5 leads to a digit whose sum is 5.
Possible solutions are: 23, 32, 41, 50, 104
i.e. w = 18, 27, 36, 45, or 99
Again 2 is insufficient.

But if we combine 1 & 2 we get w=99

Hence both are required and C is the correct answer.


The question is asking for only the tens digit, so therefore 1 is sufficient and two is insufficient since 27 and 99 can both be possible solutions.

Therefore answer is A


You are right...my bad!

I thout we had to solve for w

Posted from my mobile device
_________________
Hit Kudos if you like what you see!
GMAT Club Bot
Re: What is the tens digit of two-digit positive integer w?   [#permalink] 21 Feb 2019, 22:42
Display posts from previous: Sort by

What is the tens digit of two-digit positive integer w?

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  





Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne