The Interstate On-Ramp Is 1

Multiple Choice

The interstate on-ramp is 1.5 km West of your home,and on leaving for grandmother's house you are only able to accomplish an average velocity of 12 km/hr between your home and the on-ramp.At the onramp,you wait for traffic,for 2.0 min - and then are able to proceed toward grandmother's house.If you wish to arrive there,which is 15 km South of the onramp,over a river and through some woods,in a total elapsed time of 25.0 minutes,what average speed must you maintain on the interstate highway?

A) 51 km/hr
B) 67 km/hr
C) 36 km/hr
D) none of these.