How many pairs of positive integers (n, k) satisfy the equation 180(n-2) = 10^k?

Nnnnneeedd 1.find the residual if you know the actual number is 5.2 and the predicted value is 4.8

Ineed with number 17 i don’t get it at alll

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?