Question

The ratio of the circumferences of two circular flower beds is 3:5. lf the smaller flower bed has a radius of 9 m, what is the radius of the larger flower bed ?

• A. 15m
• B. 17m
• C. 19m
• D. 21m

Answer 1

Answer:

A. 15m

Circumference of a circle is (C = 2\pi r), so circumference is directly proportional to radius.

Given ratio of circumferences:

$3 : 5$

So the ratio of radii is also:

3 : 5

Smaller radius = 9 m corresponds to 3 parts.

So,

$3 \text{ parts} = 9 \Rightarrow 1 \text{ part} = 3$

Larger radius = 5 parts:

$5 \times 3 = 15$

Final Answer:

$\boxed{15 \text{ m}}$