Two small circular parks of diameter 16 meter and 12 meter are to be replaced by a bigger circular park. What would be the radius of this new park, if the new park has to occupy the same space as the two small parks?

A 20 meter
B 15 meter
C 10 meter
D 100 meter

Correct Answer: 10 meter

 We know,Area of circle, A = πr²  diameter of first circle  = 16m   ∴ radius =  16 2m = 8m  ∴  Area of first circle, A₁ = π x 8²= π x 64 = 201m² diameter of second circle    = 12m   ∴  radius = 12 2m = 6m  Area of second circle, A₂ = π x 6²= π x 36 = 113m²Sum of two circle, 201m² + 113m² = 314m²According to question, Large Circle:314= πr²r² = 314 πr² =314 3.14   [∵ π = 3.14]r² = 100r = √100r = 10m
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