Answer:
-(1/4πϵ0)Qq/r^2
Step-by-step explanation:
Firstly we have to assume the uniform shell of radius R as point charge as the point charge.
Then apply coulomb equation of electrostatic charge (Fe=q1q2/4πϵ0r2) where the q1 and q2 are point charges and r is the distance from the centre of charges.
But remember there's a condition that r>>R otherwise the charge will get non-uniformely distributed.