Which set of transformations has been performed on triangle xyz to form triangle x" y" z"

If f(x)=3x+1 and f^-1=x-1/3, then f^-1(7)=

Aword processing program requires a 7- digit registration code made up of the digits 1,2,4,5,6,7 and 9 each number has to be used and no number can be used mor than once how many codes are possible

The data set represents the ages of players in a chess club. 27, 34, 38, 16, 22, 45, 54, 60. what is the mean absolute deviation of the data set?