How do I approach this?

54. [R] A certain species of animal lives for at most 3 years. 50% of 0* 1 year olds survive to be 12 years old, 25% of 12 year olds survive to be 23 years old and then they all die. Each female 12 year old produces 4 female offspring in a year and each 23 year old female produces 3 female offspring in a year. a) If there are 1000 females in each age group initially, how many in each age group are there after 1, 2, 3, 4, 5 and 10 years. b) The total number of animals is clearly increasing. Divide the state vector for year Is: by the total number of animals in year A: to get a vector of the proportions of each age group in that year. Investigate the proportions as k > 00 and the yearly increase in total number of animals as k > oo