The figure is not drawn to scale. It shows the net of a solid. It is made up of 4 identical rectangles and 2 identical squares. Line R is 37 cm long and Line S is 18 cm long.
- Find the volume of the solid.
- This solid is a cardboard carton containing small boxes of chocolate bars. Each box of chocolate bars is 3 cm by 3 cm by 2 cm. If all these small boxes of chocolate bars in the carton occupy more than 75% of the carton's volume, what is the minimum number of small boxes of chocolate bars in the carton?
(a)
Breadth of the cuboid
= 18 ÷ 3
= 6 cm
Breadth of two squares
= Breadth x 2
= 6 x 2
= 12 cm
Length of the cuboid
= (37 - 12) ÷ 2
= 12.5 cm
Volume of the cuboid
= 12.5 x 6 x 6
= 450 cm
3 (b)
Volume of one box of chocolate bars
= 3 x 3 x 2
= 18 cm
3 Volume of space occupied
= 450 x 75%
= 337.5 cm
3 Estimated number of small boxes
= 337.5 ÷ 18
≈ 18.8
Minimum number of small boxes to occupy more than 75% of the carton
= 18 + 1
= 19
Answer(s): (a) 450 cm
3; (b) 19