Question

What will be our weight at center of the earth

Answer 1

Our weight at the center of the earth will be zero. Because weight(W) of a body depends on two things. One is "mass"(m), and the other is "acceleration due to gravity"(g).
the relation between them is given by W=m*g

Since the mass of the body always remains constant, and g is zero at the center of the earth, so W becomes zero.