If x and y are two positive integers and their least common multiple i

Question

If x and y are two positive integers and their least common multiple is z. Which of the following cannot be the value of z?
I. x
II. x - y 
III. x * y

(A) I only
(B) II only
(C) III only
(D) II and III only
(E) I, II and III

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GMATWhizTeam · Answer

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preetamsaha   minustark   shameekv1989   sauravleo123   prateek25   Sourav199201   debjit1990   razorhell  - Here's the 2nd question of Day 6. All the best!

prateek25 · Answer

For positive integers, x and y

a. LCM <= product of x and y 
 AND 
b.greater than or equal to both x and y

1. x : possible if y=1 from and b above
2. x-y: not possible since would not satisfy b above
3. x*y: possible from a and b above

Ans should be b

debjit1990 · Answer

Ans: B

x and y = +ve int
lcm=z

cannot be the value of z
1)x
let x,y=4
lcm=4=x..so x can be the lcm or z=x

2)x-y
this is not possible. This is the ans.

3)x*y
let x=3 y=4
lcm=12
so z=x*y..so x*y can be the lcm

gurmukh · Answer

First choice 
Let two numbers are 2 and 2 
So LCM is 2
Possible
Second choice
Let x and y are ka and kb where k is the hcf of two numbers and a and b are co- prime. Therefore kab becomes the LCM of x and y.
Now,
Ka- kb = kab
a - b = ab 
Not possible
Third choice
x=4 y =5
LCM = 20 = 4×5
Possible
Option B is the answer

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shameekv1989 · Answer

If x and y are two positive integers and their least common multiple is z. Which of the following cannot be the value of z?
I. x
II. x - y 
III. x * y

(A) I only
(B) II only
(C) III only
(D) II and III only
(E) I, II and III

Take x and y as 10, 5 => LCM = 10 => x
Take x and y as 2, 3 => LCM = 6 => x*y

x - y will yield a smaller number than x and y which can not be the LCM of x and y

Answer - B

Groo · Answer

Question: find statement that cannot be the value of z( LCM) 
I. x : can be
When x=y LCM=x

II. x -y : This statement is not related to LCM rule

III. x * y: can be true
when x and y have no common prime divisor, their LCM equals to x*y
example: x=13 and y=5 => LCM=13*5

Answer: B

If x and y are two positive integers and their least common multiple i

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If x and y are two positive integers and their least common multiple i

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615 to 715 in 15 Days (Ria's Strategies)

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