Question

A circular pool with a diameter of 18 ft will have a uniform 4 ft concrete walkway poured around it. If the concrete cost $4.25 a square foot of surface area, approximately how much will it cost for the concrete?

A. $1,174.70
B. $276.40
C. $1,714.07
D. $1,247.08

Answer 1

Answer : $1,174.70

A circular pool has diameter of 18 ft will have a uniform 4 ft concrete walkway around it.

Diameter = 18ft . So radius =
`(18)/(2) = 9ft`

Area of circular pool =
`\pi r^2= 3.14 *9*9= 254.34 ft^2`

Radius of the pool with concrete = 9 + 4= 13

Area of circular pool with concrete=
`\pi r^2= 3.14 *13*13= 530.66 ft^2`

Now surface area of concrete = area of pool with concrete - area of pool

Surface area = 530.66 - 254.34 = 276.32 square feet

the concrete cost $4.25 a square foot of surface area

So the cost for the concrete = 276.32 * 4.25 = $ 1174.36

We used the approximate value of pi that is 3.14 . so we got approximate answer

The option close to our answer is $1,174.70

$1,174.70 is the cost for the concrete