2. A cuboid of length 400 cm, breadth 220 cm
and height 120 cm is to be made. Find
the cost of polishing the box if the rate of
polishing is 24 per m2.
Answers
Given :
• Dimensions of a cuboid :-
- Length of the cuboid = 400 cm
- Breadth of the cuboid = 220 cm
- Height of the cuboid = 120 cm
- Cost of polishing 1 m² = Rs 24
To find :
- Cost of polishing the full cuboid
Solution :
Firstly, we will find the area of the cuboid.
Using formula,
Total surface area of cuboid = 2(lb + bh + hl)
where,
- l = length of the cuboid
- b = breadth of the cuboid
- h = height of the cuboid
Substitute the given values,
⇒ T.S.A of cuboid = 2(400 × 220 + 220 × 120 + 120 × 400)
⇒ T.S.A of cuboid = 2(88,000 + 26,400 + 48,000)
⇒ T.S.A of cuboid = 2(162,400)
⇒ T.S.A of cuboid = 3,24,800
Total surface area of cuboid = 3,24,800 cm²
Now, we will convert the area of cuboid from cm² into m².
As we know,
1 cm² = (1/100)² m²
Divide the value by 10,000 to convert it from cm² into m².
⇒ T.S.A of cuboid = 3,24,800/(100 × 100)
⇒ T.S.A of cuboid = 32.48 m²
Cost of polishing 1 m² of cuboidal box = Rs. 24
Cost of polishing 32.48 m² of cuboidal box = Rate × area
⇒ 24 × 32.48
⇒ 779.52
Cost of polishing the box = Rs. 779.52
Step-by-step explanation:
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