Chapter 10 - Section 10.2 - Permutations and Combinations - 10.2 Assess Your Understanding - Page 695: 25

$P(4,3)=24$

All the permutations of 4 objects 1,2,3 and 4 taken 3 at a time is $123,124,132,134,142,143,213,214,231,234,241,243,312,314,321,324,341,342,412,413,421,423,431,432$ Use the permutation formula to obtain: $P(4,3)=\frac{4!}{(4-3)!}=\frac{4!}{1!}=\frac{4\cdot3\cdot2\cdot1}{1}=24$ $P(4,3)=24$