How many loaded pallets in the shape of 1-meter cubes could you ship in a railroad boxcar that has inner dimensions 3 meters wide by 15 meters long by 4 meters high?

Johnny rode his bike to a friends house 4 blocks down the street in his neighborhood. he immediately rode back home once he realized his friend was unable to play. what was his displacement for the total bike ride trip? what could you use as a reference point ? show the steps to solve this problem.