Three point charges are placed on the x-axis. A charge of 3.00 μC is at the origin

Three point charges are placed on the x-axis. A charge of 3.00 μC is at the origin. A charge of -5.00 μC is at 20.0 cm, and a charge of 8.00 μC is at 35.0 cm.
What is the force on the charge at the origin?