Question

A solid has $12$ faces and $20$edges. How many vertices does it have?

Answer 1

Given that,

Faces = $12$

Edges = $20$

use the formula,

$$\begin{gathered} V+F-E=2 \\ V+12-20=2 \\ V-8=2 \\ V=2+8 \\ V=10 \end{gathered}$$

Hence, the number of vertices is $10$.