During the 31 nights of october , keith kept track of his sleep. he slept a total of 297 hours . how many hours of sleep did he average each night ?

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?

You give a $4 tip for a meal that cost $22. approximately what percent of the bill was your tip?

X/y + 4y/x divided by x/y - 2y/x explain as in depth as you can how you simplfied the fractions. i don't know where to start on this : /