The correct option is D 2399.65 cm2(approx)
Curved surface area of the required container = Surface area of cylinder + Surface area of frustum.
Radius of the cylinder, R = 14 cm
Height of the cylinder, h = 20 cm
Curved surface area of cylinder = 2πRh
= 2×227×14×20
= 1760 cm2
Radii of the furstum are R and r, where R is 14 cm and r is 3,5 cm.
Slant height of frustum, l = √(14−3.5)2+52 =11.63
Curved surface area of the frustum = πl(R+r)
= 227×17.5×11.63 = 639.65 cm2
∴ Total curved surface area of the container
= 1760 cm2+639.65 cm2=2399.65 cm2