SOLUTION: When the radius of a circle is multipled by 4, the area of the new circle is 40 in3. What was the area of the original circle?
Algebra.Com
Question 320791: When the radius of a circle is multipled by 4, the area of the new circle is 40 in3. What was the area of the original circle?
Found 2 solutions by Alan3354, solver91311:
Answer by Alan3354(69443) (Show Source): You can put this solution on YOUR website!
Area is a function of the square of the radius.
4x the radius --> 16 times the area.
Original = 40/16 = 2.5 sq inches, not cubic inches
Answer by solver91311(24713) (Show Source): You can put this solution on YOUR website!
The areas of two circles are in proportion as the square of the ratio of their radii. Hence your new circle is 
times larger than the old circle. By the way, area is measured in square units, not cubic units.
John
RELATED QUESTIONS
When the radius of a circle is increaded by 5, its area is increased by 32pie. What is... (answered by Alan3354)
The radius of a circle is increased by 100%. By what percent was the area of the circle... (answered by Alan3354)
If the radius of a circle is increased by 2 cm, its area increases by 16PI square... (answered by solver91311)
The area of a circle is 30in2. If you triple the circle’s radius, what will its new area... (answered by mananth)
When the radius of a circle is increased by two inches, its area is increased by 24 pi... (answered by rothauserc)
if the radius of a circle is increase by 4 units, its original area is multiplied by 2.... (answered by Earlsdon,Alan3354)
The area of a rectangle is 53.6 cm2. If the length is multipled by four and the width is... (answered by vindeep)
If the radius of a circle is decreased by 2 meters, the area of the circle is decreased... (answered by lwsshak3,MathTherapy)
If the radius of a circle is decreased by 40% , by what percent is the area decreased... (answered by Alan3354)