A circle has radius 2 cm and a second circle has radius 3 cm. By what factor is the area of the second circle larger than the first?
Answer and explanation
Correct answer: C. 9/4
- Step 1: Area is proportional to the radius squared.
- Step 2: Factor = (3/2) squared = 9/4.
Answer
9/4.
Why not the others: 3/2: areas depend on the square of the radius, not the radius itself. 5: the areas were subtracted without dividing. 27/8: the cube of the radius was used.
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