A very small charged block with a mass of 2.35 g is placed on an insulated, frictionless

Question:

A very small charged block with a mass of 2.35 g is placed on an insulated, frictionless plane inclined at an angle of 17.0° with respect to the horizontal. The block does not slide down the plane because of a 465-N/C uniform electric field that the points parallel to the surface downward along the plane. What is the sign and magnitude of the charge on the block?