What the answer pre algebra oder operating

Weak battery is considered to be a part of routine a. inspection b. wear and tear c. maintenance d. check

What is the average rate of change for this function for the interval from x=2 to x=4 ?

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?