Counting by multiplying replaces counting by listing. This course counts arrangements and selections with and without restrictions.
The course follows the NCERT Class 11 Mathematics chapter Permutations and Combinations and has 3 lessons. Each lesson explains the ideas with worked examples and ends with practice questions and full answers. The numbers in every example and question are our own, so the lessons can be used alongside the textbook exercises.
- Counting Principle and Permutations, The fundamental principle of counting, factorials, permutations with and without repetition, and arrangements of like objects.
- Combinations and Selection Problems, Combinations, their identities, and selections with conditions including committees, cards and geometry.
- Permutations and Combinations: Mixed Practice, Twelve original counting questions, with answers.
By the end you will be able to:
- Apply the fundamental principle of counting.
- Count permutations, including with repeated objects.
- Count combinations and use their identities.
- Solve restricted arrangement and selection problems.