The figure shows a rubber cuboid that measures 141 cm by 25 cm by 25 cm.
- Find the maximum number of 6-cm cubes that can be cut from the rubber cuboid.
- Find the total surface area of the L-shaped block after cutting.
(a)
Number of cubes along the length
= 141 ÷ 6
= 23 r 3
Breath = Height
Number of cubes along the breadth or height
= 25 ÷ 6
= 4 r 1
Maximum number of 6 cm cubes
= 23 x 4 x 4
= 368
(b)
Area of the 2 squares
= 2 x 25 x 25
= 1250 cm
2 Area of the top and bottom bases
= 2 x 141 x 25
= 7050 cm
2 Area of 1 L-shaped side
= 141 x 1 + (25 - 1) x 3
= 141 + 72
= 213 cm
2Area of 2 L-shaped sides
= 2 x 213
= 426 cm
2 Total surface area
= 7050 + 1250 + 426
= 8726 cm
2 Answer(s): (a) 368; (b) 8726 cm
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