Question

Greg wants to find the amount of concrete needed to cast a pillar he has designed. The pillar will have a base area of 1/28 square yard and a height of 1/14 yard. How much concrete does he need to cast the pillar?

A. 1/256 cubic yard
B. 1/392 cubic yard
C. 1/484cubic yard
D. 1/512 cubic yard

Answer 1

B. 1/392 cubic yard

Explanation:

Given,

The base area of the pillar, B =
`(1)/(28)` square yard ,

Its height, h =
`(1)/(14)` yd

Thus, the volume of the pillar would be,

`V=B* h`

`=(1)/(28)* (1)/(14)`

`=(1)/(28* 14)`

`=(1)/(392)\text{ square yard}`

Since, the concrete he needs to cast the pillar = Volume of the pillar

=
`(1)/(392)\text{ square yard}`

Option 'B' is correct.

Answer 2

B. 1/392 cubic yard

Explanation:

The volume is the product of base area and height:

V = Bh = (1/28 yd²)·(1/14 yd) = 1/(28·14) yd³ = 1/392 yd³