Answer:
both side charges will exert force on central charge towards left so the two forces add up. Thus resultant force on centre charge is
F = 9×10^9 x 8×10^-6×10×10^-6/16
+
9× 10^9 × 10×10^-6×12×10^-6/64
= 9× 10^9 × 10^ -12/16 (80+30)
=6.18 × 10^-2 N
or
= 0.06 N
