Answer: The answer is 284.
Step-by-step explanation:
The area of the garden is an annulus whose,
Outer diameter = 18 ft
Inner diameter = 18 ft - 2*3ft = 12 ft
Therefore,
Outer radius = 18/2 = 9 ft
Inner radius = 12/2 = 6 ft
Area of garden = Area of annulus
Area of garden = π*(9 ft)2 - π * (6 ft)2
Area of garden = 142
Given:
2 flowers are planted per square foot.
Therefore for 142 ft2,
Number of flowers required = 2*142 = 284
The answer is 284.