1. Lesson 2

1.6. Explore 2

Mathematics 30-2 Module 3

Module 3: Permutations, Combinations, and the Fundamental Counting Principle

 

As you may have noticed in Try This 3, writing out all the factors can take a long time. Here is another way you could simplify .

 

Expanding the numerator and denominator gives you the following:

 

 

 

As you can see, the expression in the brackets is the same as 9!; therefore, you can write as

 

Dividing numerator and denominator by the common factor of 9! leaves 12 × 11 × 10 or 1320.

 

Self-Check 2
  1. Simplify the following.
    1. Answer
    2. Answer

 

textbook

  1. Complete questions 1.a., 1.c., 1.f., 3.c., 4, 5.a., 5.c., and 5.e. on pages 81 and 82 of your textbook. Answer