Given,
Height of the circularCylinder (h1) = 12 cm
Base radius of thecircular Cylinder (r) = 5 cm
Height of the conicalhole = Height of the circular cylinder, i.e., h1 = h2 =12 cm
And, Base radius ofthe conical hole = Base radius of the circular Cylinder = 5 cm
Let’s consider, L asthe slant height of the conical hole.
Then, we know that
Now,
The total surface areaof the remaining portion in the circular cylinder (V1) = πr2 +2πrh + πrl
V1 =π(5)2 + 2π(5)(12) + π(5)(13)
V1 =210 π cm2
And, the volume of theremaining portion of the circular cylinder = Volume of the cylinder – Volume ofthe conical hole
V = πr2h– 1/3 × 22/7 × r2 × h
V = π(5)2(12)– 1/3 × 22/7 × 52 × 12
V = 200 π cm2