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

 It is currently 17 Sep 2019, 18:10

### 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

# 40% of the dogs at a certain animal shelter have been microchipped. Ho

Author Message
TAGS:

### Hide Tags

Manager
Joined: 08 Jan 2018
Posts: 98
Location: India
GPA: 4
WE: Information Technology (Computer Software)
Re: 40% of the dogs at a certain animal shelter have been microchipped. Ho  [#permalink]

### Show Tags

19 Jul 2019, 00:23
1
How many of the dogs have not been microchipped?

1. 37.5% of the dogs that have been microchipped are also either spayed or neutered.
But it does not tell us how many dogs are not microchipped.
Insufficient.

2. There are less than 50 dogs at the animal shelter
The number of dogs < 50
It again does not tell us about not microchipped dogs.
Insufficient.

Combining 1 and 2:
Let dogs are 40 =>16 dogs are microchipped and then 6 dogs are also either spayed or neutered. We cannot say anything about not microchipped dogs.
Let dogs are 20 => 8 dogs are microchipped and then 3 dogs are also either spayed or neutered. We cannot say anything about not microchipped dogs.
We don`t have the exact number of dogs.

So, IMO the answer is E.

Please hit kudos if you like the solution.
Manager
Joined: 12 Jan 2018
Posts: 112
Re: 40% of the dogs at a certain animal shelter have been microchipped. Ho  [#permalink]

### Show Tags

19 Jul 2019, 00:54
1
40% of the dogs at a certain animal shelter have been microchipped. How many of the dogs have not been microchipped?

(1) 37.5% of the dogs that have been microchipped are also either spayed or neutered.
Since the number of dogs must be integral value, least number of dogs is= $$\frac{40}{100} * \frac{375}{1000} = \frac{3}{20}$$
Therefore, minimum number of total dogs N= 20. But no. of dogs not microchipped will vary based on the N. -Not sufficient.

(2) There are less than 50 dogs at the animal shelter, _Clearly this alone not sufficient.
(1)+(2). If N=20, No.of dogs not micro chipped is 12. But if N=4, which also satifies condition in (2), no. of dogs not micro chipped will be 24. Clearly not sufficient

Ans: E
_________________
"Remember that guy that gave up?
Neither does anybody else"
Senior Manager
Joined: 18 May 2019
Posts: 255
Re: 40% of the dogs at a certain animal shelter have been microchipped. Ho  [#permalink]

### Show Tags

19 Jul 2019, 01:02
1
We are informed in the question that 40% of the dogs in an animal shelter have been microchipped. Based on the given information, we expected to determine the number of dogs that are not microchipped.

Clearly, we know that 60% of the dogs are not microchipped. We therefore need information that leads us to find the total number of dogs in the shelter to enable us find the number of dogs that are not microchipped.

Statement 1 is clearly insufficient since it does not give us any useful information or data about the total number of dogs within the shelter.

From statement 2, we know that there are less than 50 dogs in the shelter. We only know that the number of dogs is less 50, meaning if we argue for the number of dogs microchipped to be an integer, we will still have many possibilities total dogs in the shelter such as: 45, 16, 35, 30, 25, 20, 15, 10 and 5. Hence statement 2 is also insufficient on its own.

Combining 1 and 2. The additional information about the proportion of dogs that were spayed or neutered does not help to narrow down thecpossilities in statement 2 to a definite figure considering taking 37.5% of the dogs that have been microchipped results in fractions. Hence both statements are insufficient.

Posted from my mobile device
Senior Manager
Joined: 18 Jan 2018
Posts: 308
Location: India
Concentration: General Management, Healthcare
Schools: Booth '22, ISB '21, IIMB
GPA: 3.87
WE: Design (Manufacturing)
Re: 40% of the dogs at a certain animal shelter have been microchipped. Ho  [#permalink]

### Show Tags

19 Jul 2019, 01:28
1
40% of the dogs at a certain animal shelter have been microchipped. How many of the dogs have not been microchipped?

Given 40% of dogs at a shelter are microchipped .
==> 60% not microchipped . But we don't know the total no. of dogs in shelter?

(1) 37.5% of the dogs that have been microchipped are also either spayed or neutered.
We need total of dogs , which we cannot infer from the given data --- So Insufficient

(2) There are less than 50 dogs at the animal shelter
Given n<50 , lets say n = 49 then 60%of 49 = 29.4 = app 30
n =40 , then 60%of 40 =24

If total dogs change , dogs not microchipped change ---Insufficient.

Even if take data from A and B combined , we cannot find ---So Answer to this question is E
Intern
Joined: 09 Jul 2019
Posts: 38
Re: 40% of the dogs at a certain animal shelter have been microchipped. Ho  [#permalink]

### Show Tags

19 Jul 2019, 02:25
1
Given 40 percent of dogs being microchipped, and 60 percent not, we need to find what is 60 percent in numerical terms. Statement 1 does not provide us with such information neither does statement 2. Combined we are still not able to find number of dogs not microchipped as total number of dogs can be either 40 or 20. Answer is E
Manager
Joined: 22 Oct 2018
Posts: 73
Re: 40% of the dogs at a certain animal shelter have been microchipped. Ho  [#permalink]

### Show Tags

19 Jul 2019, 02:27
1
Statement 2: there are less than 50 dogs at the anial shelter.

Again no substantial information i being povided.Just that we can consider the various value for number of dogs being less than 50 i.e 49,48,..........1.

Not sufficient.

Now combining both ,if we take any value less than 50 , we have to calculate 40% of it which should be a whole number and also 37.5% of 40% of dogs also has to be a whole number.

Now if we take vlaue as 49 and calculate number of dogs which are microchipped then we get 19.6 which is not a whole number also 37.5% of it also wont be a whole number (we get 7.35)

Now if we take number of dogs a 40 and calculate 40% of it we get 16 and 37.5% of it would be 6.It seems that we have arrived at the solution .But there is another value of dogs which gives a whole number as the answers and that number is 20.We get microchipped dogs as 8 and 37.5% of it would be 3.Hence we get two values and that cant hold to be true.
Hence E IMO
Intern
Joined: 24 Mar 2018
Posts: 48
Location: India
Concentration: Operations, Strategy
Schools: ISB '21
WE: Project Management (Energy and Utilities)
Re: 40% of the dogs at a certain animal shelter have been microchipped. Ho  [#permalink]

### Show Tags

19 Jul 2019, 03:12
1
Let the total no. of dogs be x.

No. of dogs microchipped = 0.4x
No. of dogs not microchipped = 0.6x

We need to find the value of 0.6x (or simply the value of x)

Statement 1:
No. of dogs that have been microchipped that are also either spayed or neutered = 37.5% of 0.4x = 0.15x
No. of dogs that have been microchipped that are neither spayed or neutered = 0.4x-0.15x = 0.25x
This info doesn't help in finding the value of x.
Not sufficient.

Statement 2:
x<50
If x=40, no. of dogs not microchipped = 0.6x = 24
If x=30, no. of dogs not microchipped = 0.6x = 18
Not sufficient.

Statement 1 & 2:
No. of dogs that have been microchipped that are also either spayed or neutered = 37.5% of 0.4x = 0.15x
x<50
x should be an integer (and so should 0.15x)
But we cannot get a unique value for 0.15 x (consider the following 2 cases)
If x=40, 0.15x=6
If x=20, 0.15x=3
Not sufficient.

Option (E)
Senior Manager
Joined: 25 Sep 2018
Posts: 406
Location: United States (CA)
Concentration: Finance, Strategy
GMAT 1: 640 Q47 V30
GPA: 3.97
WE: Investment Banking (Investment Banking)
Re: 40% of the dogs at a certain animal shelter have been microchipped. Ho  [#permalink]

### Show Tags

19 Jul 2019, 03:49
1
40% of the dogs at a certain animal shelter have been microchipped. How many of the dogs have not been microchipped?

(1) 37.5% of the dogs that have been microchipped are also either spayed or neutered.
(2) There are less than 50 dogs at the animal shelter

Solution:

Question Stem analysis:

If there are 40 % of dogs who have been micro chipped in a set, the rest 60 % aren't.
we need a specified value for the number of dogs

Statement One Alone:

37.5% of the dogs that have been micro chipped are also either spayed or neutered. This statement does not tell us any information about the dogs who have not been micro-chipped or the total number of dogs.
Hence statement one alone is insufficient. We can eliminate A & D

Statement two alone:

Total number of dogs is less than 50. this does not gives us a specified number but this gives us a range.

Statement one & two together

We know that , the number of dogs is less than 50 and that 40 % of them are micro chipped , considering the numbers less than 50, we can test some values , for eg, 49 now 40 % of 49 is surely not an integer, we can try 40, we see that the total number of micro-chipped dogs is 16. so we have a number, but can it satisfy the first condition and be an integer? Yes. it does. 37.5 % of 16 is 6 and hence it can be the total number of dogs, but testing some further values, we notice that 40 % of 20 is 8 & 37.5 % of 8 is 3. So we are getting two different values satisfying both the conditions and hence there isn't a specific answer or value.
_________________
Why do we fall?...So we can learn to pick ourselves up again
Manager
Joined: 01 Oct 2018
Posts: 112
Re: 40% of the dogs at a certain animal shelter have been microchipped. Ho  [#permalink]

### Show Tags

19 Jul 2019, 04:43
1
40% of the dogs at a certain animal shelter have been microchipped. How many of the dogs have not been microchipped?

(1) 37.5% of the dogs that have been microchipped are also either spayed or neutered.
Give nothing. INSUFFICIENT

(2) There are less than 50 dogs at the animal shelter
n - number of dogs
n<50
If 40% of the dogs at a certain animal shelter have been microchipped, 0,4*n = integer (must be)
Possible variants:
5,10,15...45
INSUFFICIENT

(1) and (2) If 37.5% of the dogs that have been microchipped are also either spayed or neutered, than 0,4*0,375*n = integer (must be)
0,4*0,375 = 0,15
0,15*n = integer
n<50
Possible variants:
20 and 40
INSUFFICIENT

Manager
Joined: 31 Dec 2017
Posts: 83
Re: 40% of the dogs at a certain animal shelter have been microchipped. Ho  [#permalink]

### Show Tags

19 Jul 2019, 04:44
1
40% of the dogs have been microchipped---->60% of the dogs haven't been microchipped., how many of the dogs account for 60%?????
So, we need to know the total of the dogs in a real number in that shelter

ST1: We know the percentage of the dogs regarding to its types.---->Obviously not helpful to answer the question----->NS

ST2: total of the dogs < 50
--->the number of the dogs with microchip + the number of the dogs without microchip < 50------>This piece of info looks like a condition for an equation; however, we couldn't get anything from this statement to answer the question---->NS

ST1 + ST2: Still couldn't answer the question, as the we need at least 1 real number to form an equation; meanwhile, we don't have any after combining all the given info.------>My answer is E
Manager
Joined: 25 Jul 2018
Posts: 208
Re: 40% of the dogs at a certain animal shelter have been microchipped. Ho  [#permalink]

### Show Tags

19 Jul 2019, 05:02
1
The number of total dogs is 'a'
--> a*40%=a*40/100=2/5*a(microchipped dogs--it should be integer)

Statement1:

"37.5% of microchipped dogs":
--> 37.5%*(2/5*a)= (37.5/100) *(2/5*a)=3/20*a
That means 3/20*a must be integer.
Still no info about how many dogs there are. Any multiples of 20 could help to find the solution.

--> (if a=20, then 20*2/5=8 microchipped ones. 20-8 =12(not been microchipped)
--> (if a=60, then 60*2/5=24 microchipped ones. 60-24 =36(not been microchipped)
....
Insufficient.

Statement2: a<50
Also, the solution depends on 'a'
if a=45, then 45-(45*40/100)=27 (not been microchipped)
if a=35, then 35-(35*40/100)=19 (not been microchipped)
....
Insufficient

Taken together 1 and 2:
---> '3/20*a' and a<50
There are 2 multiples of 20 between 1 and 50,(not inclusive): (20 and 40) --> that means two different solutions

Insufficient

Manager
Joined: 03 Aug 2009
Posts: 58
Re: 40% of the dogs at a certain animal shelter have been microchipped. Ho  [#permalink]

### Show Tags

19 Jul 2019, 05:20
1
40% of the dogs at a certain animal shelter have been microchipped. How many of the dogs have not been microchipped?
As we are talking about alive beings, their number always has to be an integer

(1) 37.5% of the dogs that have been microchipped are also either spayed or neutered.
Not sufficient, as 37.5% could of 100 or 200 or ...1000 of dogs

(2) There are less than 50 dogs at the animal shelter
Not sufficient, as 40% could of 10, 20,30,40 (multiple of 10<50) dogs

Combined, we get that 37,5% spayed of 40% chipped of X dogs needs to be an integer less than 50. Is there is such unique integer?
$$0.375 *0.40*X = 0.15*X$$, then to be an integer X must be multiple of 20 less than 50: 20, 40
Back-test :
$$40*.4*.375 = 6$$
$$20*.4*.375 = 3$$

So, since there are 2 possibilities of X, then insufficient, answer is E.
Manager
Joined: 07 Jul 2019
Posts: 54
Re: 40% of the dogs at a certain animal shelter have been microchipped. Ho  [#permalink]

### Show Tags

19 Jul 2019, 05:37
1
For DS questions that ask for number value, we need number in statements not ratio, percentage to find answer. No statements give a value to calculate number of dogs. We could combine 1+2 but we would arrive at two different numbers of non-microchipped dogs, 24 and 12.
Manager
Joined: 24 Jun 2017
Posts: 71
Re: 40% of the dogs at a certain animal shelter have been microchipped. Ho  [#permalink]

### Show Tags

19 Jul 2019, 05:46
1
40% of the dogs at a certain animal shelter have been microchipped. How many of the dogs have not been microchipped?
So we need the number n of dogs in the shelter, and then 60% of n will not be microchipped
(1) 37.5% of the dogs that have been microchipped are also either spayed or neutered. - no info about total number n - Insufficient
(2) There are less than 50 dogs at the animal shelter. n<50 so 10 or 40. Insufficient

Both together n can only be 10,20,30,40 since 40% is microchipped and that number cannot be a decimal.
37.5/ 100 * 4 = decimal
.375 * 8
.375 * 12 = decimal
.375 * 16

So n can be 20 or 40
.375*8 = 3, 12 not microchipped
.375*16 = 6, 24 not microchipped
So E

Posted from my mobile device
Intern
Joined: 23 Jul 2017
Posts: 20
Location: India
Concentration: Technology, Entrepreneurship
GPA: 2.16
WE: Other (Other)
40% of the dogs at a certain animal shelter have been microchipped. Ho  [#permalink]

### Show Tags

19 Jul 2019, 07:47
(1) 37.5% of the dogs that have been microchipped are also either spayed or neutered.
Not sufficient alone

(2) There are less than 50 dogs at the animal shelter
Not sufficient alone

37.5%=3/8
40% =2/5
We need a mutiple of 8 and 5 because the animals will be a whole number. So any multiple of 40.
Statement 2 tells us it's less than 50, that leaves us with 40 as the only answer.
40% of the dogs at a certain animal shelter have been microchipped. Ho   [#permalink] 19 Jul 2019, 07:47

Go to page   Previous    1   2   3   4   [ 75 posts ]

Display posts from previous: Sort by