Respuesta :
This question was apprently selected from the "Sneaky Questions" category.
The store is 3 km from his home, and he walks there with a speed of 6 km/hr. Â So it takes him (3 km) / (6 km/hr) Â = Â 1/2 hour to get to the store.
That's 30 minutes. Â So the whole part-(a.) of the question refers to only that part of the trip, and we don't care what happens once he reaches the store. Â
a). Over the first 30 minutes of his travel, Greg walks 3.0 km on a straight road, and he ends up 3.0 km away from where he started.
Average speed = (distance/time) = (3.0 km) / (1/2 hour) = 6.0 km/hr
Average velocity = (displacement/time) = (3.0 km) / (1/2 hour) = 6.0 km/hr
There's probably some more questions in part-(b.) where you'd need to use Greg's return trip to find the answers, but johnaddy210 is only asking us for part-(a.).