Does anyone one know how to make a factor a decimal on the calculator

What are the first 4 terms in the multiplication pattern given by the formula 2×4n

Astandard deck of cards contains 52 cards. one card is selected from the deck. (a) compute the probability of randomly selecting a diamond or heart. (type an integer or a decimal rounded to three decimal places as needed.) (b) compute the probability of randomly selecting a diamond or heart or club. (type an integer or a decimal rounded to three decimal places as needed.) (c) compute the probability of randomly selecting queen or club. (type an integer or a decimal rounded to three decimal places as needed.)

Is (root2 -2)^2 rational or irrational. show the steps and answer fast