Please solve; help is appreciated

What is the nth term rule of the linear sequence below? 27 , 25 , 23 , 21 , 19 , . .

Abcd ≅ klmn ≅ pqrs ≅ wxyz given that information, which figures are reflections of abcd?

There are three bags: a (contains 2 white and 4 red balls), b (8 white, 4 red) and c (1 white 3 red). you select one ball at random from each bag, observe that exactly two are white, but forget which ball came from which bag. what is the probability that you selected a white ball from bag a?