A set of cards are organized into four rows. The first row has 6 cards, the second row has 10 cards, the third row has 9 cards and the fourth row has 5 cards. A person is told to randomly choose one card. What is the probability the person will choose a card from the second row?

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.