There is a bag of marbles that has 40% blue marbles, 10% red marbles, 30% green marbles, and 20% black marbles. What is the ratio of red marbles to black marbles?

Graph the line that represents a proportional relationship between d and t with the property that an increase of 33 units in t corresponds to an increase of 44 units in d. what is the unit rate of change of dd with respect to t? (that is, a change of 11 unit in t will correspond to a change of how many units in d? )