A bucket made of aluminium is of height 20cm and has its upper and lower ends of radius 36 cm and 21 cm respectively. Find the cost of preparing the bucket if the cost of aluminium is rs 50 per 100 cm square.
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Answer:
Rs 183.27
Step-by-step explanation:
See attachment
Define x:
Let x be the slanted height
Find the slanted height:
a² + b² = c²
(36 - 21)² + 20² = x²
x² = 15² + 20²
x² = 625
x = √625
x = 25
Find the lateral surface area:
Lateral Surface Area = π(R1 + r1) x Slanted Height
Lateral Surface Area = π(21 + 36) x 25 = 1425π cm²
Find the area of the base:
Area of the base = πr²
Area = π(21)² = 441π cm²
Find the total surface area:
Total surface area = 1425π + 441π = 1866π cm²
Find the cost:
100 cm² = Rs 50
1 cm² = 50 ÷ 100 = Rs 0.50
1866π cm² = 1866π x 0.5 = Rs 183.27
Answer:Rs 183.27
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dhritimaankalita298:
It's wrong❌❎❎❎❌❌❌area of the base is not πr² in frustum it's area of base is π(r²+R²)
The area of the base is a circle .. therefore πr².
I find the lateral surface area (which is the curved area) + the bottom circle. This is a bucket, therefore it is opened at the top.
I find the lateral surface area (which is the curved area) + the bottom circle. This is a bucket, therefore it is opened at the top.
π(r²+R²) is to find both the area of both the top and bottom (which is not necessary in this question.
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