The tetrahedron shown is a regular solid with four faces, each of

which is an equilateral triangle of unknown side length L$.$ At the

center of the tetrahedron is a single positive point particle with

charge q$=+20$ Q$.$ The electric flux through just the bottom face of

the tetrahedron is Q$//$epsilon$\_(0)$ times

a$)3$

b$)5$

c$)7$

d$)9$

e$)$ The answer cannot be determined without knowing L$.$

answer is b