on a trip covering 250 km , a bicyclist travels the first 100 km at 20 km per hour and the remainder of the distance at 15 km per hour . what is the average speed , in km per hour , for the entire trip ?
"time 1 = 100 / 20 = 5 hours time 2 = 150 / 15 = 10 hours total time = 15 hours average speed = 250 / 15 = 16.7 km / hr the answer is c ."
speed(250, add(divide(100, 20), divide(subtract(250, 100), 15)))