Write an algebraic expression that represents 20less than 19 times a number

The number if marbles of different colors stored in a hat is listed below: 4 red marbles 10 green marbles 7 blue marbles. without looking in the hat, dan takes out a marble at random. he replaces the marble and then takes out another marble from the hat. what is the probability that dan takes out a blue marble in both draws?

Select all the expressions that will include a remainder.

1yd 1 ft = 1 1/12 1 1/3 1 1/2 1 1/6