a train travels 240 km in 3 hours and 450 km in 5 hours . find the average speed of train .
"as we know that speed = distance / time for average speed = total distance / total time taken thus , total distance = 240 + 450 = 690 km thus , total speed = 8 hrs or , average speed = 690 / 8 or , 86 kmph . answer : c"
divide(add(240, 450), add(3, 5))