In the fraction x/y, where x and y are positive integers, what is the value of y?
(1) The least common denominator of x/y and 1/3 is 6
(2) x=1
Answer E
beat the DS Qs
This topic has expert replies
-
- Senior | Next Rank: 100 Posts
- Posts: 65
- Joined: Wed Mar 28, 2012 6:54 pm
- Location: Canada
- Thanked: 15 times
- Followed by:1 members
St.1 -- LCM of (x/y) and (1/3) is 6...that means y can be either 2 or 6
Both of them will give an LCM of 6. So, insufficient.
St.2 -- Doesn't say anything about y, so insufficient.
Combining St.1 & St.2 ....still we will have two options for y ie either 2 or 6
Thus, we choose E.
Hope this helps
Both of them will give an LCM of 6. So, insufficient.
St.2 -- Doesn't say anything about y, so insufficient.
Combining St.1 & St.2 ....still we will have two options for y ie either 2 or 6
Thus, we choose E.
Hope this helps
sachindia wrote:In the fraction x/y, where x and y are positive integers, what is the value of y?
(1) The least common denominator of x/y and 1/3 is 6
(2) x=1
Answer E
GMAT/MBA Expert
- Brent@GMATPrepNow
- GMAT Instructor
- Posts: 16207
- Joined: Mon Dec 08, 2008 6:26 pm
- Location: Vancouver, BC
- Thanked: 5254 times
- Followed by:1268 members
- GMAT Score:770
Statement 1 says, "the least common denominator of x/y and 1/3 is 6"sachindia wrote:How do you calculate the LCM of fractions?
eg lcm of 1/6 and 1/3 =?
This is the same as saying "the LCM of y and 3 is 6"
Example: The least common denominator of 3/10 and 7/15 is 30. In other words, to add 3/10 and 7/15, we'd need to first rewrite them with common denominators of 30 (i.e., 3/10 + 7/15 = 9/30 + 14/30 = 23/30). Similarly, the LCM of 10 and 15 is 30.
Cheers,
Brent
GMAT/MBA Expert
- Brent@GMATPrepNow
- GMAT Instructor
- Posts: 16207
- Joined: Mon Dec 08, 2008 6:26 pm
- Location: Vancouver, BC
- Thanked: 5254 times
- Followed by:1268 members
- GMAT Score:770
Target question: What is the value of ysachindia wrote:In the fraction x/y, where x and y are positive integers, what is the value of y?
(1) The least common denominator of x/y and 1/3 is 6
(2) x=1
Statement 1: The least common denominator of x/y and 1/3 is 6
In other words, the least common multiple (LCM) of y and 3 is 6
This means that y can equal 2 or y can equal 6
Since we cannot answer the target question with certainty, statement 1 is NOT SUFFICIENT
Statement 2: x=1
There are several values of x and y that meet this condition. Here are two.
Case a: x = 1 and y = 29573584
Case b: x = 1 and y = 2
Since we cannot answer the target question with certainty, statement 2 is NOT SUFFICIENT
Statements 1 and 2 combined:
There are still 2 sets of values for x and y that meet both conditions:
Case a: x = 1 and y = 2
Case b: x = 1 and y = 6
Since we cannot answer the target question with certainty, the combined statements are NOT SUFFICIENT
Answer = E
Cheers,
Brent