Find the value of E (Q33)

This is a little bir harden than simple math question. bonus questions in exams.

Answer:

Ax4=E, A=E/4

B/4=E, B=4E

C+4=E, C=E-4

D-4=E, D=E+4

A+B+C+D=800, E/4+4E+E-4+E+4=800, E/4+6E=800, 4(E/4+6E)=3200, 25E=3200,

E=128