Q1. Fill in the gaps with the best answer 1. There are different ways to arrange 4 books on a shelf. 2- There are - different ways to plant 5 trees in a circular area. 3- There are different ways to sit 4 people on 7 chairs. 4- There are samples of size 2 in the population {1,2,3,4,5,6}. 5- There are samples of size 3 in the population {1,2,3,4,5,6}. 6- There are -different 3 -digit numbers can be formed from the set {1,2,3,4,5,6}. 7. There are -different 4 -digit numbers can be formed from the set {1,2,3,4,5,6} without repetition. 8- There are ways to from a committee of 3 females and 2 males from a class of 10 males and 20 females. 9. 10 points are not in a straight line. Number of line segments can be formed equals 10- 10 points are not in a straight line. Number of triangles can be formed equals 11. 7 people are shaking hands once in a room. Number of shaking hands equals