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 M is 36 cm long and Line N is 15 cm long.
- Find the volume of the solid.
- This solid is a cardboard carton containing small boxes of sweets. Each box of sweets is 3 cm by 3 cm by 1 cm. If all these small boxes of sweets in the carton occupy more than 70% of the carton's volume, what is the minimum number of small boxes of sweets 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
= (36 - 10) ÷ 2
= 13 cm
Volume of the cuboid
= 13 x 5 x 5
= 325 cm
3 (b)
Volume of one box of sweets
= 3 x 3 x 1
= 9 cm
3 Volume of space occupied
= 325 x 70%
= 227.5 cm
3 Estimated number of small boxes
= 227.5 ÷ 9
≈ 25.3
Minimum number of small boxes to occupy more than 70% of the carton
= 25 + 1
= 26
Answer(s): (a) 325 cm
3; (b) 26