Valculating Permutations
A teacher has four books-A, B, C, and D-to assign to four students in any order he prefers.
Set S includes all possible arrangements of the four books,
Set X includes all possible arrangements when book C is chosen first and D is chosen second,
Which notation is correct?
If book C is chosen first and D is chosen second, in how many ways can the teacher assign the books?

Define multiplicative inverse. give an example of a number and its multiplicative inverse.

Stefano accidentally dropped his sunglasses off the edge of a canyon as he was looking down. the height, h(t), in meters (as it relates to sea level), of the sunglasses after t seconds, is shown in the table. during its descent, the pair of sunglasses passed by a climber in the canyon 6 seconds after stefano dropped them. to the nearest meter, what is difference in elevation between stefano and the climber? 166 meters 176 meters 230 meters 240 meters its b.176 i took the test 166 is wrong and 176 is correct

Arational number that is equivalent to -20/4?