Question

the inner diameter of a circular well is 4,.2 m deep.it is 12 m deep.find (1) its inner curved surface area.(2) the cost of plastering the inner curved surface at the rate of ₹50per meter square.

Answer 1

hey

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inner radius = 4.2/2 = 2.1 = 21/10m

height = 12m

inner curved surface area = 2πrh

= 2×22/7×21/10×12 m^2

= 44×36 /10m^2

=158.4 m^2

1 m^2 costs = ₹50

1584 m^2 costs = ₹ 50×1584 =₹7920.0

hope helped

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