Question

Which of the following have 1 surface flat and 1 curved surface?
A. Prism
B. Pyramid
C. Cone
D. Cylinder

Answer 1

Hint:- In this question we can draw figures and check the number of curved and flat surfaces. Also triangular faces , rectangular faces , square faces are flat surfaces in nature and circular surfaces is a curved surface in nature.

Complete step by step solution:
 Cone have 1 curved surface and 1 flat surface
If the figure you can see that there is a flat surface which is circular and another is curved surface and also a point in cone
 

Other geometries have different numbers of flat and curved surfaces in cylinder, two surfaces are flat and one surface is flat and one surface is curved.

In prism there are 5 surfaces in which 3 are rectangular and 2 are triangular.

In the pyramid there are no curved surfaces.

So, the answer is C.

Note:-
Curved surface is that in which all points on the surface are equidistant from the centre. If we open any curved surface then we will get a flat surface or if we roll a flat surface we will get a curved surface. The geometrics which have some curved surface and some flat surface we can find volume for all this type of geometries.