Answer: 72
Step-by-step explanation:
From the question, we are informed that a disc jockey can play 7 records and that there are 9 records to select from for a particular segment of a radio show.
The number of ways that the program for the segment be arranged will be:
= 9! / 7!
= (9 × 8 × 7 × 6 × 5 × 4 × 3 × 2 × 1) / (7 × 6 × 5 × 4 × 3 × 2 × 1)
= 9 × 8
= 72
