Two boxes, A and B, contain red and green balls. Box A contains 7 red and 6 green balls and box B contains 8 red and 9 green balls. If the probability to choose box A is 55% find the probability: 1. to choose box B; 2. to choose a red ball from box A; 3. to choose a red ball; 4. to choose box A if the ball that has been chosen is red.