Tony rode a bicycle from A to B in 36 km/h. After that, Tony went back from B to A in 48 km/h. It took 3 and a half hours to go from A to B and back to A. Assuming that Tony never have any rest, what is the distance between A and B?
+37158 rate x time = distance
distance/rate = time
distance AB = BA
total distance = 2 AB km
AB/36 + AB/48 = 3.5 hrs
48 AB + 36 AB = 3.5 (36 x 48)
84 AB = 6048
AB = 72 km
