x is a positive integer.find the value of x.

[BTGmoderatorDC]

x is a positive integer.find the value of x.

1)LCM of x and 26 is 52.
2)LCM of x and 10 is 20.

OA C

Source: e-GMAT

[Jay@ManhattanReview]

If x is a positive integer, what is the value of x?

1) LCM of x and 26 is 52.
2) LCM of x and 10 is 20.

OA C

Source: e-GMAT

Let's take each statement one by one.

1) LCM of x and 26 is 52.

We see that LCM = 52 = 2^2*13 and 26 = 2*13; thus, x can be either 2^2 = 4 or 2^2*13 = 52. No unique answer. Insufficient.

2) LCM of x and 10 is 20.

In the same way, x can be either 2 or 20. No unique answer. Insufficient.

(1) and (2) together

Only common value is x = 2. Sufficient.

The correct answer: C

Hope this helps!

-Jay
_________________
Manhattan Review GMAT Prep

Locations: GRE Manhattan | TOEFL Prep Courses San Diego | IELTS Prep Courses Denver | San Francisco ACT Tutoring | and many more...

Schedule your free consultation with an experienced GMAT Prep Advisor! Click here.