There are two spheres. Sphere A = +4uC, Sphere B = -6uC. C is a point in the field.

A----------(40cm)----------B----(20cm)---C

Calculate the Net Electric Field felt by C.

Electric Field Strength: $\displaystyle E = K \frac{Q_1}{r^2}$

I got it to be $\displaystyle 1 450 000 N.C^{-1}$ attraction towards B but i think this is incorrect. Any help please?