( 100+80)x=720

180x=720

x=720/ 180

x=4

Four hours later, two cars met.

Let the speed of the truck be x.

( 1.25x+x)*4=720

2.25x= 180

x=80

80* 1.25= 100

The truck speed is 80 km/h, and the car speed is100 km/h.