9. 6

11. 56

13. 362,880

15. 1

17. 56

19. 126

21. 1

23. 1

25.

1. 676

2. 650

27. 2450

29. 24

31. 60

33. 10

35. 55

37. 330

39. 20,160

41. 120

43.

1. 160

2. 800

45.

1. 12,144

2. 13,824

47. 256

49. Yes

51.

1. 5040

2. 5040

53.

1. 10

2. 10

3. 5

55. 105

57. 3,628,800

59. The maximum number of times each child will go to the circus is 20. The father will go 35 times.

61. 111,007,923,832,370,565

63. 80

65. 15

67. 360

69. 420