185k views
5 votes
Which could be the dimensions of a rectangular prism whose surface area is less than 160 square feet? Select

8 feet by 4 feet by 3 feet
7 feet by 6 feet by 4 feet
3 feet by 7 feet by 8 feet
3 feet by 6 feet by 7 feet
3 feet by 5 feet by 7 feet

1 Answer

3 votes

The dimensions of the rectangular prism could be 8 feet by 4 feet by 3 feet or 3 feet by 5 feet by 7 feet.

Explanation:

The formula for the surface area of the rectangular prism is given by,

⇒ 2lw + 2wh + 2hl

where l is length, w is width and h is the height.

Now, check for each given options whether the surface area is less than 160 or not.

8 feet by 4 feet by 3 feet

⇒ 2(8×4) + 2(4×3) + 2(3×8)

⇒ 64 + 24 + 48

⇒ 136 (less than 160)

7 feet by 6 feet by 4 feet

⇒ 2(7×6) + 2(6×4) + 2(4×7)

⇒ 84 + 48 + 56

⇒ 188 (Not less than 160)

3 feet by 7 feet by 8 feet

⇒ 2(3×7) + 2(7×8) + 2(8×3)

⇒ 42 + 112 + 48

⇒ 202 (Not less than 160)

3 feet by 6 feet by 7 feet

⇒ 2(3×6) + 2(6×7) + 2(7×3)

⇒ 36 + 84 + 42

⇒ 162 (Not less than 160)

3 feet by 5 feet by 7 feet

⇒ 2(3×5) + 2(5×7) + 2(7×3)

⇒ 30 + 70 + 42

⇒ 142 (less than 160)

User Itroulli
by
4.8k points