BTGmoderatorDC wrote:What is the circumference of circle C ?
(1) The radius of circle C is 2Ï€.
(2) The center of circle C is located at point (7,8) in the xy-plane.
Target question: What is the circumference of circle C ?
Statement 1: The radius of circle C is 2Ï€.
Useful formula: circumference = (2Ï€)(
radius)
Now that we know the radius is
2Ï€, the circumference = 2Ï€(
2Ï€) =
4π²
In other words, the answer to the target question is
the circumference of circle C is 4π²
Since we can answer the
target question with certainty, statement 1 is SUFFICIENT
Statement 2: The center of circle C is located at point (7,8) in the xy-plane.
Notice that there are infinitely many different circles that can have their center at (7,8)
This means there are infinitely many different answers to the
target question
Since we cannot answer the
target question with certainty, statement 2 is NOT SUFFICIENT
Answer: A
Cheers,
Brent
