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 J is 40 cm long and Line K is 15 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 4 cm by 2 cm by 2 cm. If all these small boxes of chocolate bars in the carton occupy more than 70% of the carton's volume, what is the minimum number of small boxes of chocolate bars in the carton?
(a)
Breadth of the cuboid
= 15 ÷ 3
= 5 cm
Breadth of two squares
= Breadth x 2
= 5 x 2
= 10 cm
Length of the cuboid
= (40 - 10) ÷ 2
= 15 cm
Volume of the cuboid
= 15 x 5 x 5
= 375 cm
3 (b)
Volume of one box of chocolate bars
= 4 x 2 x 2
= 16 cm
3 Volume of space occupied
= 375 x 70%
= 262.5 cm
3 Estimated number of small boxes
= 262.5 ÷ 16
≈ 16.4
Minimum number of small boxes to occupy more than 70% of the carton
= 16 + 1
= 17
Answer(s): (a) 375 cm
3; (b) 17