Is x a factor of y ?

Question

GMATBusters’ Quant Quiz Question -1 
For questions from past quizzes, refer this  Master topic 
Is x a factor of y ?

1) y/x = 2
2) y is a prime number

chetan2u · Accepted Answer

All the above members have gone wrong in their answer. It is very important to keep in mind that you know nothing about x. 
1) y/x=2
If both x and y are integers, answer is yes. y=6 and x=3
But y could be 1and x could be 1/2....answer is NO

2) y is a prime number. 
Nothing about x. 
If x is 1 or equal to y, answer is yes, otherwise no.

Combined. 
y=2 and x=1.....YES
But what if x is a fraction... y=3 and x=3/2....y/x=3/(3/2)=2*3/3=2
Insuff

E

deepverma · Answer

X, y can. Be integer or decimal. And decimal cannot be a factor.
A. Suppose y as 2.4 and x as 1.2
So not sufficient
B. Y is a prime number but relation to x is not given

Together we can deduce y is 2 and x is 1
So answer is C

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Archit3110 · Answer

target is x a factor of y
#1
y/x = 2
y can be 1 and x = 1/2
y= 2 and x = 1
insufficient
#2
y is a prime number
y is +ve integer , but value of x is not known
insufficient
from 1 &2
y/x ; where y must be 2 and x is 1 
sufficient
option C

Is x a factor of y ?

1) y/x = 2
2) y is a prime number

urshi · Answer

IMO : A

akadiyan · Answer

Is x a factor of y ?

1) y/x = 2
Y = 2x

This clealy shows that x is a factor of Y. Sufficient.

2) y is a prime number
There is no information about X. Not sufficient.

Ans:   A

Varunsawhney8 · Answer

Statement 1

Anything that gives integer upon dividing is a factor of that number 
So clearly statement 1 provides that x is a factor of Y
Sufficient

Statement 2 
Not sufficient
No details mentioned for X

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bratbg · Answer

IMO A
If y/x = 2 (an integer) it means that x is a factor or even if x=1 then also it is a factor.

But for B we don't know the value of x. It can be 1 or equal to y.

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gmatway · Answer

Is x a factor of y ?

1) y/x = 2 (this means its an integer so def yes) suff 
2) y is a prime number - insuff .. x could be = y or 1 a factor or may be not.

imo A

sethiamehul14 · Answer

A factor of a number must be an integer. It cannot be a fraction or a decimal.

Statement 1: We cannot say whether x and y are both integers or fractions or decimals.
Case 1: Y=6, x = 3 -> YES
Case 2: Y=7, X=3.5 -> NO
Therefore, INSUFFICIENT

Statement 2: Its given that Y is prime. Value of X is not given.
Case 1: Y = 2, X = 1 -> YES
Case 2: Y = 7, X = 3.5 -> NO
Therefore, INSUFFICIENT

Together: We still cannot conclude whether X is integer or fraction.
Case 1: Y = 2, X =1 -> YES
Case 2: Y = 7, X = 3.5 -> NO
Therefore, INSUFFICIENT

Answer is E

Addm · Answer

St 1: y/x = 2
 
 y= 2*x i.e. Y is multiple of 2 or x hence, if x is integer then it is a factor but it is fractions then it is not. hence- insufficient.

st 2: Y is prime . No information on x- insufficient

combined case,

As Y is prime number i.e means Y is integer and it is multiple of 2 which is even. in this case x can be equal to 1. which is multiple of factor of y.

but , y=2 and x=1.....YES

However, if x is a fraction...then ... y=5 and x=5/2....y/x=5/(5/2)=2*5/5=2....Insufficient

Answer: E

dep · Answer

Condition I:

y/x =2
y =2 x =1 then x is factor of y
but y= 1/2 and x=1/4 the it is not
Hence Not sufficient

Condition II:
y is prime . 
hence y is positive integer 2,3,5 etc 
x may or may not be factor
Hence Not sufficient

Combining I & II
the only option of y/x = 2/1 .
Sufficient

IMO C

Ilsecret · Answer

The answer is A

St1) y/x=2 If the division of two number is an integer, by definition the divider (in this case x) is a factor of the dividend (in this case y) 
Thus st1 Is sufficient.

St2) y Is a prime factor. We don't know anything about x so the answer can be sufficient. If for example x=1 it is for sure a factor of y.
Anyway st2 Is not sufficient.

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jhavyom · Answer

Is x a factor of y ?

For x to b a factor of y,
y/x = a where x, y, and a should be integers

1) y/x = 2
x and y can be integers or non-integers.
e. g. 
For y=2, x=1
y/x = 2/1 = 2, x is a factor of y

Also, for y=5, x=2.5
y/x = 5/2.5 = 2, x is not a factor of y
Insufficient.

2) y is a prime number
y is a prime number and nothing is known about x.

For y=2, x=1
y/x = 2/1 = 2, x is a factor of y

Also, for y=5, x=2.5
y/x = 5/2.5 = 2, x is not a factor of y
Insufficient.

Combining 1) and 2)

For y=2, x=1
y/x = 2/1 = 2, x is a factor of y

Also, for y=5, x=2.5
y/x = 5/2.5 = 2, x is not a factor of y
Insufficient.

Choice E is the answer.

123456789007 · Answer

if y/x=2 then x is a multiple of y so option A sufficient
if Y is a prime number then as per prime number definition x can be a same prime number or a can be 1 not sufficient

so answer is A

Deepakjhamb · Answer

For questions from past quizzes, refer this Master topic
Is x a factor of y ?

1) y/x = 2
2) y is a prime number

x is factor of y iff y/x =c where c , x and y are all integers

Solution :

Statement 1 : take y = 1 x =1/2 is x a factor of y ans is no
 take y= 2 and x =1 is x a factor of y ans is yes
Not sufficient

Statement 2: y =2 ( prime ) x = 2 x is factor of y , Yes
 y= 2 (prime ) x=3 x is not a factor of y , No
Not sufficient

Combined y = prime and y/x = 2 implies y = 2* x

now lets take x = 1 then y= 2 (prime ) , so x is factor of y Yes

Now lets take x = 3/2 then y = 3 ( prime) , so is 3/2 a factor of 3 , answer is no

Answer is E Neither both statements combined or alone are sufficient to answer this question

prateekchugh · Answer

Is x a factor of y ?

1) y/x = 2

y=2 x=1 YES
y=3 x=1.5 NO
Insufficient
2) y is a prime number
y=2 x=1 YES
y=3 x=1.5 NO
Insufficient
S1 + S2 is also insufficient using above two cases

Answer is E

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Is x a factor of y ?

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