To solve this, we need to find the area of the ring-shaped path. We can find this area, by calculating the area of the whole circular garden and subtracting the area of the flower garden.
The whole garden has a diameter of 34yd for the flower garden, plus the ring-shaped path, which adds 10yd to the diameter, making a total of 44yd diameter circle.
The formula for the area of a circle is:
Where r is the radius,
Let's find the area of a circle of diameter 44yd. The radius is half the diameter, thus r = 22
And now, the area of the garden without the ring-shaped path. This is a circle of diameter 34yd. Thus, the radius is 17yd.
If we now rest the area of the smaller circle to the area of the bigger circle, we get the area of the path:
And to find out how many bags of san are needed, we divide the area of the path (612.3 sq yd) by the area that a single bag can cover (6 sq yd):
Since we can't buy a fraction of a bag,
The answer is 103 bags of sand.