30. How many different ways can 6 friends be seated at the movie theater if there are 20 seats in a row and they all want to be on the same row?*
*Do not include commas in your answer.
ways

Step 1 ：This is a permutation problem. We have 20 seats and we want to find out how many ways we can arrange 6 friends in these seats. The formula for permutations is nPr = n! / (n-r)!, where n is the total number of items, and r is the number of items to choose. In this case, n is 20 (the total number of seats) and r is 6 (the number of friends).

Step 2 ：Substitute n = 20 and r = 6 into the formula.

Step 3 ：Calculate the permutation: \(\frac{20!}{(20-6)!}\)

Step 4 ：The result is a float because the division operation returns a float. However, the number of ways should be an integer because we cannot have a fraction of a way. Therefore, convert the result to an integer.

Step 5 ：Final Answer: The number of different ways the 6 friends can be seated in a row of 20 seats is \(\boxed{27907200}\).