Calculate magnitude and direction of the electric field

Question

Two equal positive charges of magnitude q₁ = q₂ = 2 nC are on the y axis at y₁ = +3 cm and y₂ = -3 cm.

a) What is the magnitude and direction of the electric field on the x axis at x = 3 cm? ??? N/C  + ??? N/C 

b) What is the force exerted on a third charge q₀ = 5  nC when it is placed on the xaxis at x = 3 cm? ??? N/C  + ??? N/C