SAT math counting problems

[Jack]

SAT math counting problems

I need help with the following question:

"In how many different ways can 4 students be seated in two seats?"

Thanks!!

[Oliver]

SAT maths counting problem permutations

"In how many different ways can 4 students be seated in two seats?"

The number of ways you can change the order of a set of objects is called the number of PERMUTATIONS of that set of objects.

The total number of ways of arranging n objects, taking r at a time is gibe by the following formula:

, where

So, in your case, you have 4 students taking 2 at a time

ways.

The above calculations could be done easily in your GDC casio fx-9860GII SD for example as follows:

OPTN>PROB>nPr and set n=4 and r=2


Another way to solve this problem is that the first seat can be filled with 4 ways and the second with the remaining 3ways(students). So, the total ways are 4x3=12


Hope these help!!

[Jack]

Thanks Oliver!!