On a radio tower, a red light flashes every 6 seconds and a blue light flashes every 10 seconds. if both lights flash together at a certain time, how many seconds later will both lights flash together the next time?

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.