On a 120 km track, a train travels the first 30 km at speed of 30 km/h how fast must the train travel the next 90km so as to average 60km/h for the entire tip?
On a 120 km track, a train travels the first 30 km at speed of 30 km/h how fast must the train travel the next 90km so as to average 60km/h for the entire tip?