2
Answer: ASet 3: Circles (Intermediate)
Explanation
PROBLEM
Recent studies show that a circle has circumference 14pi. What is its radius?
A circle has circumference 14pi. What is its radius?
A.✓ Correct
7
B.
5
C.
14
D.
8
Detailed Explanation
[Variation 1] Choice A is the best answer. C = 2 times pi times r. 14pi = 2 times pi times r. r = 7
Why others are wrong:
B: 5 is incorrect because it does not satisfy the equation.
C: 14 is incorrect because it does not satisfy the equation.
D: 8 is incorrect because it does not satisfy the equation.