A number decreased by 30% and the result was 7560. What was the original number? A.2268 B.9828 C.5292 D.10800

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.