Question

Ram has a hemispherical bowl of radius 7 cm. if one bottle of paint can paint 14 cm2, then how many bottles are needed to paint the bowl from outside?

Answer 1

Solution :-

Radius of the hemispherical bowl = 7 cm

Outer curved surface area of the hemispherical bowl = 2πr²

⇒ (2*22*7*7)/7

⇒ 308 cm²

To paint area of 14 cm², bottle of paint is needed = 1

To paint area of 1 cm², bottle of paint is needed = 1/14

To paint area of 308 cm², bottle of paint is needed = (1*308)/14

= 22 bottle

So, 22 bottle paint will be needed.

Answer.

Answer 2

Given:

Radius of the hemispherical bowl (r)= 7 cm

1 bottle of paint can paint = 14 cm²


Outer curved surface area of the hemispherical bowl (c.s.a) = 2πr²

= (2×22/7×7×7) =( 44×49)/7= 44×7

=308 cm²

Number of bottles needed to paint the bowl from outside= outer c.s.a of hemispherical bowl/ area to be painted by 1 bottle

= 308/14= 154/7= 22

= 22 bottle

Hence, 22 bottles of paint will be needed to paint the bowl from outside.

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Hope this will help you...