7
Answer: BSet 4: Circles (Intermediate)
Explanation
PROBLEM
Intriguingly, a circle has circumference 14pi. What is its radius?
A circle has circumference 14pi. What is its radius?
A.
5
B.✓ Correct
7
C.
9
D.
14
Detailed Explanation
[Variation 2] Choice B is the best answer. C = 2 times pi times r. 14pi = 2 times pi times r. r = 7
Why others are wrong:
A: 5 is incorrect because it does not satisfy the equation.
C: 9 is incorrect because it does not satisfy the equation.
D: 14 is incorrect because it does not satisfy the equation.