Two circular ponds have circumferences in the ratio 4 : 7. If the smaller pond has an area of 200 m2, what is the approximate area of the larger pond?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 613 m2.
Circumference of circle is directly proportional to its radius, i.e. ratio of radius of circle = ratio of circumferences of the circle
Let the radius of smaller and larger circles be 4x and 7x respectively.
Given, Area of smaller circle = (4x)2 = 16x2
Area of larger circle = (7x)2 = 49x2
Given, 16x2 = 200
⇒ x2 = 12.5
Now, 49x2 = 49 × 12.5 = 612.5 ≈ 613