Answer:
B
Step-by-step explanation:
Euler's formula for polyhedra states that
F + V - E = 2
where F is faces, V is vertices and E is edges
Substitute the values given and solve for F, that is
F + 13 - 26 = 2
F - 13 = 2 ( add 13 to both sides )
F = 15 → B
The answer to number 16 is 0,15