A toddler applies a 25.0 N force to a chair over a distance of 2.5 m, the chair is being pushed across a smooth floor against a force of friction (10.0 N resistance). How much work is being done?

Force applied * distance in direction of force

= 25 * 2.5

It is not clear what besides friction the force is overcoming, perhaps acclerating, but it does not matter. Work done by the force is still the force times the distance.