The area of a circle is increased by 1500%. By what percent has the diameter of the circle increased?	Choose the correct choice from the following answers
A) 100% B) 500% C) 300% D) 600% E) 800%
The area of the circle is increased by 1500%, thus the area is increased 16 times.   The area of a circle it proportional to the square of the diameter (area=πd^2/4), therefore the diameter must increase 4 times (diameter increase 4 times = area increase 16 times), which is increase by 500%.   Answer: 500%.
<result>B</result>
The area of a circle is increased by 1500%. By what percent has the diameter of the circle increased?