From a solid cylinder whose height is 2.4 cm and diameter 1.4 cm, a conical cavity of the same height and same diameter is hollowed out. Find the total surface area of the remaining solid to the nearest cm2.

Height of conical part = Height of cylindrical part (h) = 2.4 cm
Diameter of cylindrical part = 1.4 m, so, the radius of cylindrical part (r) = 0.7 m
Slant height of cylindrical part (l) = √(r²+ h²)
= √((0.7)² + (2.4)²) = √(0.49 + 5.76) = √(6.25) = 2.5
The total surface area of the remaining solid
= CSA of cylindrical + CSA of conical part + Area of base of cylinder
= 2πrh + πrl + πr²
= 2 × 22/7 × 0.7 × 2.4 + 22/7 × 0.7 × 2.5 + 22/7 × 0.7 × 0.7
= 4.4 × 2.4 + 2.2 × 2.5 × 0.7 = 10.56 + 5.50 + 1.56 = 17.60 cm².