BTGmoderatorDC wrote: ↑Wed Mar 09, 2022 6:21 pm
What is the value of x?
1) The Greatest Common Factor of 90 and x is 30
2) The Least Common Multiple of 90 and x is 900
OA
C
Source: Veritas Prep
Target question: What is the value of x?
Statement 1: The Greatest Common Factor of 90 and x is 30
There are several values of x that satisfy statement 1. Here are two:
Case a:
x = 30
Case b:
x = 60
Since we can’t answer the
target question with certainty, statement 1 is NOT SUFFICIENT
Statement 2: The Least Common Multiple of 90 and x is 900
There are several values of x that satisfy statement 2. Here are two:
Case a:
x = 900
Case b:
x = 300
Since we can’t answer the
target question with certainty, statement 2 is NOT SUFFICIENT
Statements 1 and 2 combined
There's a nice rule that says:
(greatest common divisor of x and y)(least common multiple of x and y) = xy
So, for this question, we get:
(greatest common divisor of 90 and x)(least common multiple of 90 and x) = 90x
Substitute values:
(30)(900) = 90x
Divide both sides of the equation by 90 to get:
(30)(10) = x
Evaluate:
x = 300
Since we can answer the
target question with certainty, the combined statements are SUFFICIENT
Answer: C
Cheers,
Brent
