a) List the first 10 positive multiples of 9, starting with 1.9=9. b) List the first 10 positive multiples of 15, starting with 1.15-15. c) Use parts a) and b) to determine the least natural number that is a multiple of both 9 and 15. a) The first 10 positive multiples of 9 are (Use a comma to separate answers as needed.)