Abag contains 15 marbles. 7 are blue, 4 are red, 2 marbles are green and 2 marbles are yellow. a marble is taken from the bag at random. what is the probability that it is: blue? yellow? red? green? either blue or red? either red or yellow? blue, green or yellow? not yellow?

There are a total sales of 2,000 dollars on monday on tuesday sales dropped 10% on wednesday sales dropped another 20% compared with tuesday from wednesday to thursday sales increases by an equal amount to 25% of monday total sales what is the net change in dollars on total sales from monday to tuesday