Question

Fabian needs 4 1/2 square feet of posterboard for an art project. He buys a sheet of posterboard with a length of 30 inches and a width of 2 feet. Which option correctly explains why this is enough posterboard for the project?

Answer 1

It is enough because the one he purchased is 5 square feet

Explanation:

Now, before we can go ahead to determine if the sheet will be enough, we need to first find out how many inches that make a foot since one of the dimensions of the sheet is in inches.

12 inches make 1 foot

Then, if 12 inches make a foot, we will then calculate the equivalent of 30 inches being the length of the sheet of the poster board that Fabian just purchased.

12 inches ---------- 1 foot

30 inches ---------- ? feet

30/12 × 1

= 5/2

= 2.5 feet.

Therefore, 30 inches will make 2 feet.

Now, it is clear that the length of the sheet of poster board is 2.5 feet while the width is 2 feet. If Fabian requires or needs 4 1/2 square feet (4.5 square feet) of poster board, we can then calculate if this one he bought will be enough for his project:-

The area of a rectangle = length × width/breadth.

Length = 2.5 feet

width = 2 feet

The area of this poster board is then:

2.5 × 2 = 5 square feet.

If Fabian needs 4.5 square feet sheet of poster board for his school project, it is now obvious that this one he purchased will be more than enough because he will still have 0.5 or half a square foot surplus afterwards.

Answer 2

Answer: 720 is greater than 648

Explanation:

The required posterboard for an art project = 4 1/2 square feet

1 square foot = 144 square inches

4 1/5 × 144 square inches

= 648 square inches.

The available posterboard is with a length of 30 inches and a width of 2 feet.

One foot = 12 inches

The area of the available posterboard 30 × 2 × 12 = 780 inches

Since the available area is greater than the required area, the posterboard will therefore be enough for the project.