A 120-meter-long bridge with a 6-meter wide deck is designed to carry a maximum of 20 tons of weight per axle. If a truck with two axles and a total weight of 40 tons drives onto the bridge, what is the maximum allowable distance between the axles of the truck to prevent the bridge from collapsing?

Assume the bridge is made of reinforced concrete with a compressive strength of 30 MPa, and the dead weight of the bridge itself is 400 kN. The live load factor for this type of bridge is 1.75 and the impact factor is 1.33.