Question

Six charges, three +ve and three -ve of equal magnitude are placed at the vertices of a regular hexagon such that electric field at O is double the electric field when only one positive charg of the same magnitude is placed at R. which of the following arrangements is possible for P,Q,R,S,T and U respectively?
a) +,-,+,-,-,+
b)+,-,+,-,+,-
c)+,+,-,+,-,-
d)-,+,+,-,+,-

Answer 1

Diagram please??