Tourists covered 640 km for a 4-hour ride by car and a 7-hour ride by train. What is the speed of the train, if it is 5 km greater than the speed of the car?

Question

 How is this possible?

Answer 1

distance=rate*time

640=r*4+(r+5)*7

640=4r+7r+35

640=11r+35

640-35=11r

605=11r

r=605/11

r=55 kph

r=55=5=60 kph is the speed of the train

check: 55*4+60*7=220+420=640 km