Help electrostatics - electric field(beginner level)

Mar 2019
The figure below shows three electric charges q1, q2 and q3 that are located at distances of r1= 2 cm, r2= 2cm and r3= 1cm from the origin of the coordinate system, as shown in the figure. Knowing that θ1 = θ2 = θ3 = 30º, q1=1mC,q2=3mC and q3=-2mC. Consider: 1/4πξº = 9x10 ^ 9 Nm² / C², and determine:
a) the electrostatic potential at the origin of the coordinate system. b) the electric field modulus of the charge q2 acting on the charge q3.