Can someone that is knowledgeable of the subject help me?

The lines shown below are parallel. if the green line has a slope of -1, what is the slope of the red line?

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?

What is the mean of the data set 125, 141, 213, 155, 281