There are 15 European cities that Kevin would eventually like to visit. On his next vacation, though, he only has time to visit 4 of the cities: one on Monday, one on Tuesday, one on Wednesday, and one on Thursday. He is now trying to make a schedule of which city he'll visit on which day. How many different schedules are possible?

32760 different schedules are possible.

Step-by-step explanation:

The order is important.

For example

Prague on Monday, Berlin on Tuesday, Liverpool on Wednesday and Athens on Thursday is a different schedule than Berlin on Monday, Prague on Tuesday, Liverpool on Wednesday and Athens on Thursday.

So we use the permutations formula to solve this question.

Permutations formula:

The number of possible permutations of x elements from a set of n elements is given by the following formula:

How many different schedules are possible?

Choose 4 cities among a set of 15. So

32760 different schedules are possible.

$9.89

step-by-step explanation:

9.90 = p x .06 x .25 (3/12 changed to a decimal)

9.90 = p x 0.015

9.90 - 0.015 = p

9.89 = p

6mm^3 or .6cm^3

      216

      /   \

  36     6

  /   \     /

6     6   6

factor trees are nice.