Time = (distance) / (speed)
Time = (450 km) / (100 m/s)
Time = (450,000 m) / (100 m/s)
Time = 4500 seconds (that's 75 minutes)
Note:
This is about HALF the speed of the passenger jet you fly in when you go to visit Grandma for Christmas.
If the International Space Station flew at this speed, it would immediately go ker-PLUNK into the ocean.
The speed of the International Space Station in its orbit is more like 3,100 m/s, not 100 m/s.