What is the value of x?
(1) X^2 – 4 = 0
(2) X satisfies the equation y^2 = x where y is real
value of x?
This topic has expert replies
- Stuart@KaplanGMAT
- GMAT Instructor
- Posts: 3225
- Joined: Tue Jan 08, 2008 2:40 pm
- Location: Toronto
- Thanked: 1710 times
- Followed by:614 members
- GMAT Score:800
(1) x could be +/-2, so insufficientritula wrote:What is the value of x?
(1) X^2 – 4 = 0
(2) X satisfies the equation y^2 = x where y is real
(2) if y is a real number, then y^2 must be greater than or equal to 0, which means that x is greater than or equal to 0. That's a lot of possible values: insufficient.
Together, statement (2) means that x can no longer be negative, so the only value of x that satisfies both rules is +2: choose (c), together sufficient.
Stuart Kovinsky | Kaplan GMAT Faculty | Toronto
Kaplan Exclusive: The Official Test Day Experience | Ready to Take a Free Practice Test? | Kaplan/Beat the GMAT Member Discount
BTG100 for $100 off a full course