PSLE Betty had some identitical cuboids with square base and height, h. She then stacked the cuboid to form the 2 towers. The figure shows the front view and the side views of the 2 towers.
- Find h.
- Find the volume of the cuboid.
Tower A:
2 h + 1 b = 52 --- (1)
Tower B:
3 h + 2 b = 85 --- (2)
Make b the same.
(1)
x2 = (3)
4 h + 2 b = 104 --- (3)
(3) - (2)
(4 h + 2 b) - (3 h + 2 b) = 104 - 85
4 h - 3 h = 19
1 h = 19 cm
(b)
Substitute 1 h = 19 into (1).
2 h + 1 b = 52
2 x 19 + 1 b = 52
38 + 1 b = 52
1 b = 52 - 38 = 14
Volume of the cuboid
= 14 x 14 x 19
= 3724 cm
3 Answer(s): (a) 19 cm; (b) 3724 cm
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