Aschool club sold 220 shirts for a fundraiser. adult shirts cost $20 each and child shirts cost $15 each. the total collected for all the shirts sold was $3,550. how many adult-size shirts were sold?

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?