!!Need someone to check answers - Combinatorics Problems
36. Solve for n.
a) P (n,5) = 20P (n,3)
No clue how to do this; - please help me solve!
37. A library shelf contains 7 different books. In how many ways can they be arranged if
a) there are no restrictions
Answer: They can be arranged in 5040 different ways 7! = 5040
b) the Mathematics of Data Management textbook must be first
Answer: 6! x 1 = 720 different ways
c) the 3 mathematics textbooks must be together
Answer: - when the 3 textbooks go together, they can be counted as one textbook
Therefore, 4! x 1 = 24 different ways.