Question

Matilda is filling a circular section of her porch with colorful pebbles. She knows the diameter of the circular section is 15ft, and each bag of pebbles covers 10ft. How many bags of pebbles will Matilda need? A. 15 bags B. 16 bags C. 17 bags D. 18 bags

Answer 1

D. 18 bags

Explanation:

Given:

Matilda is filling a circular section of her porch with colorful pebbles.

Diameter of circular section = 15 feet.

Each bag of pebbles covers 10 square feet.

Question asked:

How many bags of pebbles will Matilda need?

Solution:

Diameter of circular section = 15 feet

Radius, r =
`(Diameter)/(2)=(15)/(2) =7.5\ feet`

`Area\ of\ circular\ section=\pi r^(2)`

`=(22)/(7) *7.5*7.5=(1237.5)/(7)=176.78} \ square\ feet`

10 square feet is covered by number of bag of pebbles = 1

1 square feet is covered by number of bag of pebbles =
`(1)/(10)`

176.78 square feet is covered by number of bags of pebbles =

`(1)/(10)*176.78=17.67`

We found up to 17 bags of pebbles there is still some place left to fill the section:-

Thus, Matilda need about 18 bags of pebbles to fill the circular section of her porch.