A factory manufactures 120000 pencils daily. The pencils are cylindrical in shape each of length 25 cm and circumference of base as 1.5 cm. What is the cost of coloring the curved surfaces of the pencils manufactured in one day at Rs 0.05 per $d m 2$ ?

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Rs.2250

Rs.2350

Rs.2280

Rs.3200

answer is A.

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Detailed Solution

Given that a factory manufactures 120000 pencils daily.
The pencils are cylindrical in shape each of length and circumference of base as

h = 25

cm, and

C = 1.5

cm respectively.
the cost of coloring the curved surfaces of the pencils manufactured in one day at Rs 0.05 per

d m 2

where

1 cm = 0.1 dm .

So, we have,

l = h 2 + r 1 2 − r 2 2, r 1, r 2

Now, curved surface area of one pencil is,

π l r 1 + r 2

And curved surface area of 120000 pencils will be,

π l r 1 + r 2,

The cost of coloring:

c = 0.05 A 1 c = 0.05 45000 c = R s .2250

Therefore, option 1 is correct.

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