Han and Leila live 7 miles apart. They decide to start walking toward each other's houses at the same time. Leila walks at a rate of 2.5 miles per hour and Han walks at a rate of 3 miles
per hour. How long will it take for them to meet?

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?