JAMB - Mathematics (1978 - No. 22)
A pyramid is constructed on a cuboid. The figure has
twelve faces
thirteen vertices
fourteen edges
fifteen edges
sixteen edges
Selitys
The pyramid has 8 edges in itself while the cuboid has 12 edges. When merging the two shapes together, the edge of the base of the pyramid becomes same as the edges of the top of the cuboid.
Hence, the new structure will have (12 + 8) - 4 = 16 edges.