You have a jar filled with marbles. some are orange and some are blue. you also have a supply of marbles of each color outside the jar. we carry out the following process. we reach in and pick two marbles out of the jar. if they are both orange we remove them and add a blue marble from our external supply of marbles. if they are both blue we put one back and remove the other. if one is blue and one is orange we put the orange one back and remove the blue one. we continue until there is only one marble left. what is the color of this last marble?

Mrs. julien’s and mrs. castillejo’s classes are selling cookie dough for a school fundraiser. customers can buy packages of macadamia nut chip cookie dough and packages of triple chocolate cookie dough. mrs. julien’s class sold 25 packages of macadamia nut chip cookie dough and 30 packages of triple chocolate cookie dough for a total of $221.25. mrs. castillejo’s class sold 5 packages of macadamia nut chip cookie dough and 45 packages of triple chocolate cookie dough for a total of $191.25. (a) write the system of equations that model the problem. be sure to explain which equation represents which situation. (b) find the cost of each type of cookie. show your work. (c) explain which method you used to solve the system and why you chose that method.