A solid cone of radius 
and height 
is placed over a solid cylinder having same base radius and height as that of a cone. The total surface area of the combined solid is 
False
When a solid cone is placed over a solid cylinder of same base radius, the base of cone and top of the cylinder will not be covered in total surface area.
As the height of cone and cylinder is same
Total surface area of shape formed = Total surface area of cone + Total Surface area of cylinder - 2(Area of base)
[ As Total surface area of cone = πrl + πr2,
where r = base radius and l = slant height and
Total surface area of cylinder = 2πrh + 2πr2h,
where r = base radius and h = height]
= πr(r + l) + (2πrh + 2πr2) - 2(πr2)
= πr2 + πrl + 2πrh + 2πr2 - 2πr2
= πr(r + l + h)
[ As slant height, 
]
