The figure shows a wooden cuboid that measures 141 m by 30 m by 30 m.
- Find the maximum number of 7-m cubes that can be cut from the wooden cuboid.
- Find the total surface area of the L-shaped block after cutting.
(a)
Number of cubes along the length
= 141 ÷ 7
= 20 r 1
Breath = Height
Number of cubes along the breadth or height
= 30 ÷ 7
= 4 r 2
Maximum number of 7 m cubes
= 20 x 4 x 4
= 320
(b)
Area of the 2 squares
= 2 x 30 x 30
= 1800 m
2 Area of the top and bottom bases
= 2 x 141 x 30
= 8460 m
2 Area of 1 L-shaped side
= 141 x 2 + (30 - 2) x 1
= 282 + 28
= 310 m
2Area of 2 L-shaped sides
= 2 x 310
= 620 m
2 Total surface area
= 8460 + 1800 + 620
= 10880 m
2 Answer(s): (a) 320; (b) 10880 m
2