Please i need steps and i want the answer and steps in a paper and i only have an hour

1- Find the mean of the number of girls in a family with three children. 2- class contains 30 female and 25 male students. 15 students are selected at random one after the other with replacement. X represents the number of males. 3- A coin is tossed ten times, find the probability that four heads will be obtained. 4- A ball is picked at random from a box containing 3 white, 5 red 8 blue, and 7 green, Find the probability of each event a- white ball is picked b- white or red ball is picked