Question

A cylindrical tank has a capacity 6160 m^2.Find its depth if its radius is 14m.Calculate the cost of painting its curved surface at the rate of rs.3per m^2

Answer 1

let h be the depth of cylindrical tank.

Given, capacity of cylindrical tank = 6160 m^2

radius ( r ) = 14 m

capacity of cylinderical tank = volume of cylinder.

Find the depth :
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volume of cylindrical tank = 6160 m^2

πr^2h = 6160

( 22 / 7 ) × (14 )^2 × h = 6160

196h = 6160 × 7/22

h = ( 6160× 7) / (196 × 22 )

h = 10 m

depth of cylinder = 10 m

Find the CSA :
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curved surface area of cylindrical tank = 2πrh

= 2 ×(22/ 7 )×14×10 = (2×22×14 ×10 )/ 7

= 6160 ÷ 7 = 880 m^2

Find the cost :
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cost of painting 1 m^2 = Rs 3

cost of painting 880 m^2=880 × 3 = Rs2640

therefore , cost of painting its curved surface area = Rs 2640

Answer : cost = Rs 2640

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