A Charge of +80 μC Is Placed on the X

Multiple Choice

A charge of +80 μC is placed on the x axis at x = 0. A second charge of −50 μC is placed on the x axis at x = 50 cm. What is the magnitude of the electrostatic force on a third charge of 4.0 μC placed on the x axis at x = 30 cm?

A) 13 N
B) 77 N
C) 39 N
D) 25 N
E) 45 N