Question

In a toy factory,200 wooden closed cylinders of diameter 35mm and height 7cm have to be painted. What is the total surface area, in cm,that needs to be painted (take pi to be 3.14)

Answer 1

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$</p><p>\huge{\fbox {\fbox{\rightarrow {\mathfrak {\purple{QUESTION \: - }}}}}}$

• In a toy factory,200 wooden closed cylinders of diameter 35mm and height 7cm have to be painted. What is the total surface area, in cm,that needs to be painted ?

• Take pi to be 3.14.

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$</p><p>{\huge{\boxed{\boxed{\red{\mathfrak{\rightarrow {Csa \:= \:2πrh }}}}}}}$

$</p><p>{\huge{\boxed{\boxed{\orange{\mathfrak{\therefore {Csa \: Of \: 1 \: Cylinder \: = \: 76.93 cm ^2 }}}}}}}$

$</p><p>{\huge{\boxed{\boxed{\blue{\mathfrak{\therefore {Csa \: Of \: 200 \: Cylinders\: = \: 15386 cm ^2 }}}}}}}$

$</p><p>\huge{\tt{\pink{Hope\: This \: Helps!!!}}}$

Answer 2

Given :-

• Diameter of Cylinder = 35mm.
• Height = 7cm.

Formula used :-

• Painted Area of cylinder = Curved Surface Area of cylinder = 2 * π * r * h ...
• 1 cm = 10mm .

Solution :-

→ Diameter = 35mm = (35/10) = 3.5cm.

→ Radius = (D/2) = (3.5)/2 = 1.75cm.

So,

→ CSA of 1 Cylinder = 2 * 3.14 * 1.75 * 7

And,

→ CSA of 200 such Cylinders = 200 * [ 2 * 3.14 * 1.75 * 7 ]

→ Required CSA = 1400 * 6.28 * 1.75 = 15386cm².

Hence ,, The total surface area, in cm,that needs to be painted is 15386cm².