What Goes Up

My body is long. I am very healthy.

You can make juice from me. I wear an orange coat. 

I grow underground.

Who I am?

Can you solve it?

E + E + E = 15

E + C = 8

C + E + B = 10

B + C * J = ????

People buy me to eat but never eat me.

What I am?

What has one eye but can’t see?

Where does Friday come before Thursday?