Question

Which could be the dimensions of a rectangular prism whose surface area is less than 160 square feet? Select two options.

V
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
Help please

Answer 1

Since the prism is the of rectangular dimension,and surface area of rectangular prism is 160

Surface area=2(wl+hl+hw)

Taking first option

l=9,w=4,h=3

Surface area=150 square feet which is less than according to our design criteria

Now considering option B,

l=7,w=6,h=4

Surface area=188 square ft which is more than 160,and our design will fail.

Now considering option C

l=3,w=7,h=8

Surface area=202 square ft

which is more than 160 square ft

Now considering option D

l=3,w=5,h=7

Surface area=142 square ft and it is less than 160 square.

So,according to design criteria,option A and option D is correct.